21950988 has 12 divisors (see below), whose sum is σ = 51219000. Its totient is φ = 7316992.

The previous prime is 21950987. The next prime is 21951043. The reversal of 21950988 is 88905912.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21950988² = 963691748352288, which contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21950983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 914613 + ... + 914636.

It is an arithmetic number, because the mean of its divisors is an integer number (4268250).

Almost surely, 2^21950988 is an apocalyptic number.

It is an amenable number.

21950988 is an abundant number, since it is smaller than the sum of its proper divisors (29268012).

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

21950988 is a wasteful number, since it uses less digits than its factorization.

21950988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1829256 (or 1829254 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 42.

The square root of 21950988 is about 4685.1881499039. The cubic root of 21950988 is about 279.9956972128.

The spelling of 21950988 in words is "twenty-one million, nine hundred fifty thousand, nine hundred eighty-eight".