30720000 has 150 divisors (see below), whose sum is σ = 102364108. Its totient is φ = 8192000.

The previous prime is 30719987. The next prime is 30720007. The reversal of 30720000 is 2703.

It is a tau number, because it is divible by the number of its divisors (150).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a Saint-Exupery number, since it is equal to the product of the sides of a Pythagorean triangle: 400 × 240 × 320.

It is not an unprimeable number, because it can be changed into a prime (30720007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 6143998 + ... + 6144002.

Almost surely, 2^30720000 is an apocalyptic number.

30720000 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 30720000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51182054).

30720000 is an abundant number, since it is smaller than the sum of its proper divisors (71644108).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

30720000 is an frugal number, since it uses more digits than its factorization.

30720000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51 (or 10 counting only the distinct ones).

The product of its (nonzero) digits is 42, while the sum is 12.

The square root of 30720000 is about 5542.5625842204. The cubic root of 30720000 is about 313.1894112935.

Multiplying 30720000 by its sum of digits (12), we get a square (368640000 = 19200²).

30720000 divided by its sum of digits (12) gives a 4-th power (2560000 = 40⁴).

Adding to 30720000 its reverse (2703), we get a palindrome (30722703).

The spelling of 30720000 in words is "thirty million, seven hundred twenty thousand".