21726731775 has 24 divisors (see below), whose sum is σ = 41053177984. Its totient is φ = 9932220000.

The previous prime is 21726731737. The next prime is 21726731777. The reversal of 21726731775 is 57713762712.

It is not a de Polignac number, because 21726731775 - 2⁹ = 21726731263 is a prime.

It is a super-3 number, since 3×21726731775³ (a number of 32 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21726731777) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20691601 + ... + 20692650.

Almost surely, 2^21726731775 is an apocalyptic number.

21726731775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21726731775 is a deficient number, since it is larger than the sum of its proper divisors (19326446209).

21726731775 is a wasteful number, since it uses less digits than its factorization.

21726731775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41384271 (or 41384266 counting only the distinct ones).

The product of its digits is 864360, while the sum is 48.

The spelling of 21726731775 in words is "twenty-one billion, seven hundred twenty-six million, seven hundred thirty-one thousand, seven hundred seventy-five".