21012672 has 28 divisors (see below), whose sum is σ = 55596536. Its totient is φ = 7004160.

The previous prime is 21012671. The next prime is 21012679. The reversal of 21012672 is 27621012.

It is a super-3 number, since 3×21012672³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21012671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54529 + ... + 54912.

Almost surely, 2^21012672 is an apocalyptic number.

It is an amenable number.

21012672 is an abundant number, since it is smaller than the sum of its proper divisors (34583864).

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

21012672 is a wasteful number, since it uses less digits than its factorization.

21012672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109456 (or 109446 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 21012672 is about 4583.9581149919. The cubic root of 21012672 is about 275.9479002688.

Adding to 21012672 its reverse (27621012), we get a palindrome (48633684).

The spelling of 21012672 in words is "twenty-one million, twelve thousand, six hundred seventy-two".