64720087393 has 6 divisors (see below), whose sum is σ = 70081514934. Its totient is φ = 59741618976.

The previous prime is 64720087381. The next prime is 64720087423. The reversal of 64720087393 is 39378002746.

It can be written as a sum of positive squares in 3 ways, for example, as 1078925409 + 63641161984 = 32847^2 + 252272^2 .

It is not a de Polignac number, because 64720087393 - 2²¹ = 64717990241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64720087363) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 191479380 + ... + 191479717.

It is an arithmetic number, because the mean of its divisors is an integer number (11680252489).

Almost surely, 2^64720087393 is an apocalyptic number.

It is an amenable number.

64720087393 is a deficient number, since it is larger than the sum of its proper divisors (5361427541).

64720087393 is a wasteful number, since it uses less digits than its factorization.

64720087393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 382959123 (or 382959110 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 49.

The spelling of 64720087393 in words is "sixty-four billion, seven hundred twenty million, eighty-seven thousand, three hundred ninety-three".