77821492 has 36 divisors (see below), whose sum is σ = 164287200. Its totient is φ = 31592592.

The previous prime is 77821487. The next prime is 77821553. The reversal of 77821492 is 29412877.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6259 + ... + 13957.

Almost surely, 2^77821492 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77821492, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82143600).

77821492 is an abundant number, since it is smaller than the sum of its proper divisors (86465708).

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

77821492 is a wasteful number, since it uses less digits than its factorization.

77821492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7748 (or 7727 counting only the distinct ones).

The product of its digits is 56448, while the sum is 40.

The square root of 77821492 is about 8821.6490521897. The cubic root of 77821492 is about 426.9396774309.

The spelling of 77821492 in words is "seventy-seven million, eight hundred twenty-one thousand, four hundred ninety-two".