21064938 has 16 divisors (see below), whose sum is σ = 44608320. Its totient is φ = 6608576.

The previous prime is 21064937. The next prime is 21064943. The reversal of 21064938 is 83946012.

It is a super-2 number, since 2×21064938² = 887463225887688, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21064899 and 21064908.

It is not an unprimeable number, because it can be changed into a prime (21064937) 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, 103158 + ... + 103361.

It is an arithmetic number, because the mean of its divisors is an integer number (2788020).

Almost surely, 2^21064938 is an apocalyptic number.

21064938 is an abundant number, since it is smaller than the sum of its proper divisors (23543382).

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

21064938 is a wasteful number, since it uses less digits than its factorization.

21064938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206541.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 21064938 is about 4589.6555426306. The cubic root of 21064938 is about 276.1765044071.

The spelling of 21064938 in words is "twenty-one million, sixty-four thousand, nine hundred thirty-eight".