77819990 has 16 divisors (see below), whose sum is σ = 140329152. Its totient is φ = 31071744.

The previous prime is 77819941. The next prime is 77820007. The reversal of 77819990 is 9991877.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 974 + ... + 12513.

It is an arithmetic number, because the mean of its divisors is an integer number (8770572).

Almost surely, 2^77819990 is an apocalyptic number.

77819990 is a deficient number, since it is larger than the sum of its proper divisors (62509162).

77819990 is a wasteful number, since it uses less digits than its factorization.

77819990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14071.

The product of its (nonzero) digits is 285768, while the sum is 50.

The square root of 77819990 is about 8821.5639203035. The cubic root of 77819990 is about 426.9369306853.

It can be divided in two parts, 7781 and 9990, that added together give a palindrome (17771).

The spelling of 77819990 in words is "seventy-seven million, eight hundred nineteen thousand, nine hundred ninety".