77687028 has 36 divisors (see below), whose sum is σ = 197124928. Its totient is φ = 25796880.

The previous prime is 77687021. The next prime is 77687033. The reversal of 77687028 is 82078677.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-4 number, since 4×77687028⁴ (a number of 33 digits) contains 4444 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77687021) 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, 5775 + ... + 13737.

Almost surely, 2^77687028 is an apocalyptic number.

It is an amenable number.

77687028 is an abundant number, since it is smaller than the sum of its proper divisors (119437900).

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

77687028 is a wasteful number, since it uses less digits than its factorization.

77687028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8244 (or 8239 counting only the distinct ones).

The product of its (nonzero) digits is 263424, while the sum is 45.

The square root of 77687028 is about 8814.0245064329. The cubic root of 77687028 is about 426.6936395166.

The spelling of 77687028 in words is "seventy-seven million, six hundred eighty-seven thousand, twenty-eight".