21629952 has 66 divisors (see below), whose sum is σ = 62482628. Its totient is φ = 7206912.

The previous prime is 21629947. The next prime is 21629953. The reversal of 21629952 is 25992612.

It is a happy number.

21629952 is a `hidden beast` number, since 21 + 629 + 9 + 5 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21629953) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8043 + ... + 10389.

Almost surely, 2^21629952 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 21629952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31241314).

21629952 is an abundant number, since it is smaller than the sum of its proper divisors (40852676).

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

21629952 is a wasteful number, since it uses less digits than its factorization.

21629952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2373 (or 2352 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 21629952 is about 4650.8012212951. The cubic root of 21629952 is about 278.6239972925.

The spelling of 21629952 in words is "twenty-one million, six hundred twenty-nine thousand, nine hundred fifty-two".