30023440 has 80 divisors (see below), whose sum is σ = 72839088. Its totient is φ = 11501568.

The previous prime is 30023431. The next prime is 30023443. The reversal of 30023440 is 4432003.

It can be written as a sum of positive squares in 8 ways, for example, as 80656 + 29942784 = 284^2 + 5472^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (30023443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 309472 + ... + 309568.

Almost surely, 2^30023440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 30023440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36419544).

30023440 is an abundant number, since it is smaller than the sum of its proper divisors (42815648).

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

30023440 is a wasteful number, since it uses less digits than its factorization.

30023440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236 (or 230 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 16.

The square root of 30023440 is about 5479.3649267046. The cubic root of 30023440 is about 310.8041556721.

Adding to 30023440 its reverse (4432003), we get a palindrome (34455443).

The spelling of 30023440 in words is "thirty million, twenty-three thousand, four hundred forty".