21999952 has 20 divisors (see below), whose sum is σ = 45904180. Its totient is φ = 10153728.

The previous prime is 21999917. The next prime is 21999973. The reversal of 21999952 is 25999912.

It can be written as a sum of positive squares in 2 ways, for example, as 14470416 + 7529536 = 3804^2 + 2744^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52677 + ... + 53092.

It is an arithmetic number, because the mean of its divisors is an integer number (2295209).

Almost surely, 2^21999952 is an apocalyptic number.

It is an amenable number.

21999952 is an abundant number, since it is smaller than the sum of its proper divisors (23904228).

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

21999952 is a wasteful number, since it uses less digits than its factorization.

21999952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105790 (or 105784 counting only the distinct ones).

The product of its digits is 131220, while the sum is 46.

The square root of 21999952 is about 4690.4106430034. The cubic root of 21999952 is about 280.2037292807.

The spelling of 21999952 in words is "twenty-one million, nine hundred ninety-nine thousand, nine hundred fifty-two".