77724972 has 72 divisors (see below), whose sum is σ = 222746160. Its totient is φ = 22654080.

The previous prime is 77724961. The next prime is 77724979. The reversal of 77724972 is 27942777.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (77724979) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4522 + ... + 13262.

Almost surely, 2^77724972 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 77724972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111373080).

77724972 is an abundant number, since it is smaller than the sum of its proper divisors (145021188).

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

77724972 is a wasteful number, since it uses less digits than its factorization.

77724972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8783 (or 8778 counting only the distinct ones).

The product of its digits is 345744, while the sum is 45.

The square root of 77724972 is about 8816.1767223667. The cubic root of 77724972 is about 426.7630969651.

The spelling of 77724972 in words is "seventy-seven million, seven hundred twenty-four thousand, nine hundred seventy-two".