77640035781 has 16 divisors (see below), whose sum is σ = 129063955968. Its totient is φ = 40332486000.

The previous prime is 77640035779. The next prime is 77640035783. The reversal of 77640035781 is 18753004677.

It is an interprime number because it is at equal distance from previous prime (77640035779) and next prime (77640035783).

It is not a de Polignac number, because 77640035781 - 2¹ = 77640035779 is a prime.

It is a super-2 number, since 2×77640035781² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 77640035781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77640035783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 168051795 + ... + 168052256.

It is an arithmetic number, because the mean of its divisors is an integer number (8066497248).

Almost surely, 2^77640035781 is an apocalyptic number.

It is an amenable number.

77640035781 is a deficient number, since it is larger than the sum of its proper divisors (51423920187).

77640035781 is a wasteful number, since it uses less digits than its factorization.

77640035781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336104072.

The product of its (nonzero) digits is 987840, while the sum is 48.

The spelling of 77640035781 in words is "seventy-seven billion, six hundred forty million, thirty-five thousand, seven hundred eighty-one".