66715707531 has 32 divisors (see below), whose sum is σ = 100425888000. Its totient is φ = 39024478080.

The previous prime is 66715707529. The next prime is 66715707557. The reversal of 66715707531 is 13570751766.

It is a happy number.

It is not a de Polignac number, because 66715707531 - 2¹ = 66715707529 is a prime.

It is a super-2 number, since 2×66715707531² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66715707581) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2779620 + ... + 2803518.

It is an arithmetic number, because the mean of its divisors is an integer number (3138309000).

Almost surely, 2^66715707531 is an apocalyptic number.

66715707531 is a deficient number, since it is larger than the sum of its proper divisors (33710180469).

66715707531 is a wasteful number, since it uses less digits than its factorization.

66715707531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26859.

The product of its (nonzero) digits is 926100, while the sum is 48.

The spelling of 66715707531 in words is "sixty-six billion, seven hundred fifteen million, seven hundred seven thousand, five hundred thirty-one".