21791952 has 120 divisors (see below), whose sum is σ = 75106304. Its totient is φ = 5743872.

The previous prime is 21791921. The next prime is 21791969. The reversal of 21791952 is 25919712.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12273 + ... + 13935.

Almost surely, 2^21791952 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 21791952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37553152).

21791952 is an abundant number, since it is smaller than the sum of its proper divisors (53314352).

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

21791952 is a wasteful number, since it uses less digits than its factorization.

21791952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1697 (or 1688 counting only the distinct ones).

The product of its digits is 11340, while the sum is 36.

The square root of 21791952 is about 4668.1850863050. The cubic root of 21791952 is about 279.3178633361.

The spelling of 21791952 in words is "twenty-one million, seven hundred ninety-one thousand, nine hundred fifty-two".