64378165205751 has 4 divisors (see below), whose sum is σ = 85837553607672. Its totient is φ = 42918776803832.

The previous prime is 64378165205681. The next prime is 64378165205791. The reversal of 64378165205751 is 15750256187346.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 64378165205751 - 2²¹ = 64378163108599 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64378165205791) 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, 10729694200956 + ... + 10729694200961.

It is an arithmetic number, because the mean of its divisors is an integer number (21459388401918).

Almost surely, 2^{64378165205751} is an apocalyptic number.

64378165205751 is a deficient number, since it is larger than the sum of its proper divisors (21459388401921).

64378165205751 is a wasteful number, since it uses less digits than its factorization.

64378165205751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21459388401920.

The product of its (nonzero) digits is 42336000, while the sum is 60.

The spelling of 64378165205751 in words is "sixty-four trillion, three hundred seventy-eight billion, one hundred sixty-five million, two hundred five thousand, seven hundred fifty-one".