21255455177 has 8 divisors (see below), whose sum is σ = 23193287712. Its totient is φ = 19318542400.

The previous prime is 21255455099. The next prime is 21255455191. The reversal of 21255455177 is 77155455212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21255455177 - 2¹⁸ = 21255193033 is a prime.

It is a super-2 number, since 2×21255455177² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21255451177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 181163 + ... + 274464.

It is an arithmetic number, because the mean of its divisors is an integer number (2899160964).

Almost surely, 2^21255455177 is an apocalyptic number.

It is an amenable number.

21255455177 is a deficient number, since it is larger than the sum of its proper divisors (1937832535).

21255455177 is a wasteful number, since it uses less digits than its factorization.

21255455177 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459879.

The product of its digits is 490000, while the sum is 44.

The spelling of 21255455177 in words is "twenty-one billion, two hundred fifty-five million, four hundred fifty-five thousand, one hundred seventy-seven".