21900672 has 64 divisors (see below), whose sum is σ = 64647600. Its totient is φ = 7299072.

The previous prime is 21900667. The next prime is 21900677. The reversal of 21900672 is 27600912.

It is an interprime number because it is at equal distance from previous prime (21900667) and next prime (21900677).

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21900677) 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, 288 + ... + 6624.

Almost surely, 2^21900672 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 21900672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32323800).

21900672 is an abundant number, since it is smaller than the sum of its proper divisors (42746928).

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

21900672 is an equidigital number, since it uses as much as digits as its factorization.

21900672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6360 (or 6342 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21900672 is about 4679.8153809739. The cubic root of 21900672 is about 279.7815983973.

The spelling of 21900672 in words is "twenty-one million, nine hundred thousand, six hundred seventy-two".