77640938 has 16 divisors (see below), whose sum is σ = 123680520. Its totient is φ = 36427776.

The previous prime is 77640931. The next prime is 77640943. The reversal of 77640938 is 83904677.

It can be written as a sum of positive squares in 4 ways, for example, as 55011889 + 22629049 = 7417^2 + 4757^2 .

It is not an unprimeable number, because it can be changed into a prime (77640931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8768 + ... + 15236.

Almost surely, 2^77640938 is an apocalyptic number.

77640938 is a deficient number, since it is larger than the sum of its proper divisors (46039582).

77640938 is a wasteful number, since it uses less digits than its factorization.

77640938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6841.

The product of its (nonzero) digits is 254016, while the sum is 44.

The square root of 77640938 is about 8811.4095353695. The cubic root of 77640938 is about 426.6092401824.

It can be divided in two parts, 776 and 40938, that added together give a palindrome (41714).

The spelling of 77640938 in words is "seventy-seven million, six hundred forty thousand, nine hundred thirty-eight".