77720380 has 24 divisors (see below), whose sum is σ = 163487520. Its totient is φ = 31035840.

The previous prime is 77720369. The next prime is 77720411. The reversal of 77720380 is 8302777.

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, 10281 + ... + 16159.

It is an arithmetic number, because the mean of its divisors is an integer number (6811980).

Almost surely, 2^77720380 is an apocalyptic number.

It is an amenable number.

77720380 is an abundant number, since it is smaller than the sum of its proper divisors (85767140).

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

77720380 is a wasteful number, since it uses less digits than its factorization.

77720380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6549 (or 6547 counting only the distinct ones).

The product of its (nonzero) digits is 16464, while the sum is 34.

The square root of 77720380 is about 8815.9162881688. The cubic root of 77720380 is about 426.7546923959.

The spelling of 77720380 in words is "seventy-seven million, seven hundred twenty thousand, three hundred eighty".