21379364397 has 16 divisors (see below), whose sum is σ = 32145868480. Its totient is φ = 14040178416.

The previous prime is 21379364387. The next prime is 21379364401. The reversal of 21379364397 is 79346397312.

21379364397 is a `hidden beast` number, since 213 + 7 + 9 + 36 + 4 + 397 = 666.

It is not a de Polignac number, because 21379364397 - 2⁶ = 21379364333 is a prime.

It is a super-2 number, since 2×21379364397² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21379364327) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5907358 + ... + 5910975.

It is an arithmetic number, because the mean of its divisors is an integer number (2009116780).

Almost surely, 2^21379364397 is an apocalyptic number.

21379364397 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21379364397 is a deficient number, since it is larger than the sum of its proper divisors (10766504083).

21379364397 is a wasteful number, since it uses less digits than its factorization.

21379364397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11818409 (or 11818403 counting only the distinct ones).

The product of its digits is 5143824, while the sum is 54.

The spelling of 21379364397 in words is "twenty-one billion, three hundred seventy-nine million, three hundred sixty-four thousand, three hundred ninety-seven".