64807666972381 has 4 divisors (see below), whose sum is σ = 65413346103072. Its totient is φ = 64201987841692.

The previous prime is 64807666972361. The next prime is 64807666972393. The reversal of 64807666972381 is 18327966670846.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 64807666972381 - 2¹⁹ = 64807666448093 is a prime.

It is a super-2 number, since 2×64807666972381² (a number of 28 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 (64807666972361) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 302839565185 + ... + 302839565398.

It is an arithmetic number, because the mean of its divisors is an integer number (16353336525768).

Almost surely, 2^{64807666972381} is an apocalyptic number.

It is an amenable number.

64807666972381 is a deficient number, since it is larger than the sum of its proper divisors (605679130691).

64807666972381 is a wasteful number, since it uses less digits than its factorization.

64807666972381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 605679130690.

The product of its (nonzero) digits is 877879296, while the sum is 73.

The spelling of 64807666972381 in words is "sixty-four trillion, eight hundred seven billion, six hundred sixty-six million, nine hundred seventy-two thousand, three hundred eighty-one".