77506147618681 has 4 divisors (see below), whose sum is σ = 81585418546000. Its totient is φ = 73426876691364.

The previous prime is 77506147618609. The next prime is 77506147618721. The reversal of 77506147618681 is 18681674160577.

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 77506147618681 - 2³⁹ = 76956391804793 is a prime.

It is a super-2 number, since 2×77506147618681² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77506147618181) 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, 2039635463631 + ... + 2039635463668.

It is an arithmetic number, because the mean of its divisors is an integer number (20396354636500).

Almost surely, 2^{77506147618681} is an apocalyptic number.

It is an amenable number.

77506147618681 is a deficient number, since it is larger than the sum of its proper divisors (4079270927319).

77506147618681 is a wasteful number, since it uses less digits than its factorization.

77506147618681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4079270927318.

The product of its (nonzero) digits is 94832640, while the sum is 67.

The spelling of 77506147618681 in words is "seventy-seven trillion, five hundred six billion, one hundred forty-seven million, six hundred eighteen thousand, six hundred eighty-one".