21120738 has 16 divisors (see below), whose sum is σ = 42296256. Its totient is φ = 7031120.

The previous prime is 21120733. The next prime is 21120763. The reversal of 21120738 is 83702112.

It is not an unprimeable number, because it can be changed into a prime (21120731) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4108 + ... + 7688.

It is an arithmetic number, because the mean of its divisors is an integer number (2643516).

Almost surely, 2^21120738 is an apocalyptic number.

21120738 is an abundant number, since it is smaller than the sum of its proper divisors (21175518).

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

21120738 is a wasteful number, since it uses less digits than its factorization.

21120738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4569.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 21120738 is about 4595.7304098478. The cubic root of 21120738 is about 276.4201487920.

The spelling of 21120738 in words is "twenty-one million, one hundred twenty thousand, seven hundred thirty-eight".