27391897772421 has 64 divisors (see below), whose sum is σ = 47378209374720. Its totient is φ = 13687037844480.

The previous prime is 27391897772417. The next prime is 27391897772441. The reversal of 27391897772421 is 12427779819372.

It is not a de Polignac number, because 27391897772421 - 2² = 27391897772417 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27391897772441) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 32220810 + ... + 33060011.

It is an arithmetic number, because the mean of its divisors is an integer number (740284521480).

Almost surely, 2^{27391897772421} is an apocalyptic number.

27391897772421 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

27391897772421 is a deficient number, since it is larger than the sum of its proper divisors (19986311602299).

27391897772421 is a wasteful number, since it uses less digits than its factorization.

27391897772421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65280926.

The product of its digits is 149361408, while the sum is 69.

The spelling of 27391897772421 in words is "twenty-seven trillion, three hundred ninety-one billion, eight hundred ninety-seven million, seven hundred seventy-two thousand, four hundred twenty-one".