21058172475 has 12 divisors (see below), whose sum is σ = 34816178616. Its totient is φ = 11231025280.

The previous prime is 21058172453. The next prime is 21058172479. The reversal of 21058172475 is 57427185012.

It is not a de Polignac number, because 21058172475 - 2⁶ = 21058172411 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21058172479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 140387742 + ... + 140387891.

It is an arithmetic number, because the mean of its divisors is an integer number (2901348218).

Almost surely, 2^21058172475 is an apocalyptic number.

21058172475 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21058172475 is a deficient number, since it is larger than the sum of its proper divisors (13758006141).

21058172475 is a wasteful number, since it uses less digits than its factorization.

21058172475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280775646 (or 280775641 counting only the distinct ones).

The product of its (nonzero) digits is 156800, while the sum is 42.

The spelling of 21058172475 in words is "twenty-one billion, fifty-eight million, one hundred seventy-two thousand, four hundred seventy-five".