21489672 has 32 divisors (see below), whose sum is σ = 53877600. Its totient is φ = 7142784.

The previous prime is 21489661. The next prime is 21489697. The reversal of 21489672 is 27698412.

It is a self number, because there is not a number n which added to its sum of digits gives 21489672.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8988 + ... + 11124.

It is an arithmetic number, because the mean of its divisors is an integer number (1683675).

Almost surely, 2^21489672 is an apocalyptic number.

It is an amenable number.

21489672 is an abundant number, since it is smaller than the sum of its proper divisors (32387928).

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

21489672 is a wasteful number, since it uses less digits than its factorization.

21489672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2565 (or 2561 counting only the distinct ones).

The product of its digits is 48384, while the sum is 39.

The square root of 21489672 is about 4635.6954170868. The cubic root of 21489672 is about 278.0203563239.

The spelling of 21489672 in words is "twenty-one million, four hundred eighty-nine thousand, six hundred seventy-two".