30123720 has 96 divisors (see below), whose sum is σ = 106816320. Its totient is φ = 7301760.

The previous prime is 30123719. The next prime is 30123733. The reversal of 30123720 is 2732103.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 30123693 and 30123702.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 157 + ... + 7763.

It is an arithmetic number, because the mean of its divisors is an integer number (1112670).

Almost surely, 2^30123720 is an apocalyptic number.

30123720 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 30123720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53408160).

30123720 is an abundant number, since it is smaller than the sum of its proper divisors (76692600).

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

30123720 is a wasteful number, since it uses less digits than its factorization.

30123720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7635 (or 7628 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 18.

The square root of 30123720 is about 5488.5079939816. The cubic root of 30123720 is about 311.1498056558.

Adding to 30123720 its reverse (2732103), we get a palindrome (32855823).

The spelling of 30123720 in words is "thirty million, one hundred twenty-three thousand, seven hundred twenty".