77640966 has 36 divisors (see below), whose sum is σ = 182164788. Its totient is φ = 23888592.

The previous prime is 77640961. The next prime is 77640971. The reversal of 77640966 is 66904677.

It is an interprime number because it is at equal distance from previous prime (77640961) and next prime (77640971).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77640961) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 9720 + ... + 15803.

It is an arithmetic number, because the mean of its divisors is an integer number (5060133).

Almost surely, 2^77640966 is an apocalyptic number.

77640966 is an abundant number, since it is smaller than the sum of its proper divisors (104523822).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77640966 is a wasteful number, since it uses less digits than its factorization.

77640966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25557 (or 25541 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 45.

The square root of 77640966 is about 8811.4111242184. The cubic root of 77640966 is about 426.6092914657.

It can be divided in two parts, 77640 and 966, that added together give a triangular number (78606 = T₃₉₆).

The spelling of 77640966 in words is "seventy-seven million, six hundred forty thousand, nine hundred sixty-six".