77031639509 has 4 divisors (see below), whose sum is σ = 84034515840. Its totient is φ = 70028763180.

The previous prime is 77031639493. The next prime is 77031639527. The reversal of 77031639509 is 90593613077.

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 77031639509 - 2⁴ = 77031639493 is a prime.

It is a super-2 number, since 2×77031639509² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77031639709) 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, 3501438149 + ... + 3501438170.

It is an arithmetic number, because the mean of its divisors is an integer number (21008628960).

Almost surely, 2^77031639509 is an apocalyptic number.

It is an amenable number.

77031639509 is a deficient number, since it is larger than the sum of its proper divisors (7002876331).

77031639509 is a wasteful number, since it uses less digits than its factorization.

77031639509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7002876330.

The product of its (nonzero) digits is 1071630, while the sum is 50.

The spelling of 77031639509 in words is "seventy-seven billion, thirty-one million, six hundred thirty-nine thousand, five hundred nine".