21586720775 has 12 divisors (see below), whose sum is σ = 26771296200. Its totient is φ = 17266949280.

The previous prime is 21586720763. The next prime is 21586720777. The reversal of 21586720775 is 57702768512.

It is not a de Polignac number, because 21586720775 - 2²⁸ = 21318285319 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21586720777) 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, 132836 + ... + 246614.

It is an arithmetic number, because the mean of its divisors is an integer number (2230941350).

Almost surely, 2^21586720775 is an apocalyptic number.

21586720775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21586720775 is a deficient number, since it is larger than the sum of its proper divisors (5184575425).

21586720775 is a wasteful number, since it uses less digits than its factorization.

21586720775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121378 (or 121373 counting only the distinct ones).

The product of its (nonzero) digits is 1646400, while the sum is 50.

The spelling of 21586720775 in words is "twenty-one billion, five hundred eighty-six million, seven hundred twenty thousand, seven hundred seventy-five".