21555053575 has 12 divisors (see below), whose sum is σ = 29158109208. Its totient is φ = 15676402400.

The previous prime is 21555053573. The next prime is 21555053581. The reversal of 21555053575 is 57535055512.

It is not a de Polignac number, because 21555053575 - 2¹ = 21555053573 is a prime.

It is a super-2 number, since 2×21555053575² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21555053573) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39190732 + ... + 39191281.

It is an arithmetic number, because the mean of its divisors is an integer number (2429842434).

Almost surely, 2^21555053575 is an apocalyptic number.

21555053575 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21555053575 is a deficient number, since it is larger than the sum of its proper divisors (7603055633).

21555053575 is a wasteful number, since it uses less digits than its factorization.

21555053575 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78382034 (or 78382029 counting only the distinct ones).

The product of its (nonzero) digits is 656250, while the sum is 43.

The spelling of 21555053575 in words is "twenty-one billion, five hundred fifty-five million, fifty-three thousand, five hundred seventy-five".