21955700 has 36 divisors (see below), whose sum is σ = 51311820. Its totient is φ = 8106240.

The previous prime is 21955691. The next prime is 21955709. The reversal of 21955700 is 755912.

It is an interprime number because it is at equal distance from previous prime (21955691) and next prime (21955709).

It can be written as a sum of positive squares in 6 ways, for example, as 7772944 + 14182756 = 2788^2 + 3766^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21955709) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 7145 + ... + 9744.

Almost surely, 2^21955700 is an apocalyptic number.

21955700 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21955700 is an abundant number, since it is smaller than the sum of its proper divisors (29356120).

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

21955700 is a wasteful number, since it uses less digits than its factorization.

21955700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16916 (or 16909 counting only the distinct ones).

The product of its (nonzero) digits is 3150, while the sum is 29.

The square root of 21955700 is about 4685.6909842626. The cubic root of 21955700 is about 280.0157304088.

The spelling of 21955700 in words is "twenty-one million, nine hundred fifty-five thousand, seven hundred".