21642672 has 60 divisors (see below), whose sum is σ = 59055000. Its totient is φ = 6829056.

The previous prime is 21642667. The next prime is 21642727. The reversal of 21642672 is 27624612.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16704 + ... + 17952.

It is an arithmetic number, because the mean of its divisors is an integer number (984250).

Almost surely, 2^21642672 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 21642672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29527500).

21642672 is an abundant number, since it is smaller than the sum of its proper divisors (37412328).

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

21642672 is a wasteful number, since it uses less digits than its factorization.

21642672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1298 (or 1273 counting only the distinct ones).

The product of its digits is 8064, while the sum is 30.

The square root of 21642672 is about 4652.1685266121. The cubic root of 21642672 is about 278.6786037127.

The spelling of 21642672 in words is "twenty-one million, six hundred forty-two thousand, six hundred seventy-two".