77640550 has 24 divisors (see below), whose sum is σ = 155521296. Its totient is φ = 28667040.

The previous prime is 77640529. The next prime is 77640553. The reversal of 77640550 is 5504677.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77640553) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 59074 + ... + 60373.

It is an arithmetic number, because the mean of its divisors is an integer number (6480054).

Almost surely, 2^77640550 is an apocalyptic number.

77640550 is an abundant number, since it is smaller than the sum of its proper divisors (77880746).

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

77640550 is a wasteful number, since it uses less digits than its factorization.

77640550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119472 (or 119467 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 34.

The square root of 77640550 is about 8811.3875184332. The cubic root of 77640550 is about 426.6085295407.

The spelling of 77640550 in words is "seventy-seven million, six hundred forty thousand, five hundred fifty".