21623952 has 80 divisors (see below), whose sum is σ = 64440320. Its totient is φ = 6120576.

The previous prime is 21623939. The next prime is 21623963. The reversal of 21623952 is 25932612.

It is a super-3 number, since 3×21623952³ (a number of 23 digits) contains 333 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46473 + ... + 46935.

It is an arithmetic number, because the mean of its divisors is an integer number (805504).

Almost surely, 2^21623952 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 21623952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32220160).

21623952 is an abundant number, since it is smaller than the sum of its proper divisors (42816368).

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

21623952 is a wasteful number, since it uses less digits than its factorization.

21623952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 620 (or 614 counting only the distinct ones).

The product of its digits is 6480, while the sum is 30.

The square root of 21623952 is about 4650.1561264112. The cubic root of 21623952 is about 278.5982321162.

The spelling of 21623952 in words is "twenty-one million, six hundred twenty-three thousand, nine hundred fifty-two".