21386952 has 96 divisors (see below), whose sum is σ = 62295480. Its totient is φ = 6604800.

The previous prime is 21386947. The next prime is 21386971. The reversal of 21386952 is 25968312.

It can be written as a sum of positive squares in 4 ways, for example, as 19660356 + 1726596 = 4434^2 + 1314^2 .

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

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 23 ways as a sum of consecutive naturals, for example, 123538 + ... + 123710.

Almost surely, 2^21386952 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 21386952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31147740).

21386952 is an abundant number, since it is smaller than the sum of its proper divisors (40908528).

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

21386952 is a wasteful number, since it uses less digits than its factorization.

21386952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303 (or 296 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 21386952 is about 4624.6029018717. The cubic root of 21386952 is about 277.5766722640.

The spelling of 21386952 in words is "twenty-one million, three hundred eighty-six thousand, nine hundred fifty-two".