21537055 has 12 divisors (see below), whose sum is σ = 26147016. Its totient is φ = 17030000.

The previous prime is 21537049. The next prime is 21537073. The reversal of 21537055 is 55073512.

It is not a de Polignac number, because 21537055 - 2¹³ = 21528863 is a prime.

It is a Duffinian number.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 85680 + ... + 85930.

It is an arithmetic number, because the mean of its divisors is an integer number (2178918).

Almost surely, 2^21537055 is an apocalyptic number.

21537055 is a deficient number, since it is larger than the sum of its proper divisors (4609961).

21537055 is an equidigital number, since it uses as much as digits as its factorization.

21537055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 518 (or 387 counting only the distinct ones).

The product of its (nonzero) digits is 5250, while the sum is 28.

The square root of 21537055 is about 4640.8032709866. The cubic root of 21537055 is about 278.2245438403.

The spelling of 21537055 in words is "twenty-one million, five hundred thirty-seven thousand, fifty-five".