77309980 has 48 divisors (see below), whose sum is σ = 178569216. Its totient is φ = 27881280.

The previous prime is 77309977. The next prime is 77309989. The reversal of 77309980 is 8990377.

It is a Smith number, since the sum of its digits (43) 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 (77309989) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26557 + ... + 29323.

It is an arithmetic number, because the mean of its divisors is an integer number (3720192).

Almost surely, 2^77309980 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 77309980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89284608).

77309980 is an abundant number, since it is smaller than the sum of its proper divisors (101259236).

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

77309980 is a wasteful number, since it uses less digits than its factorization.

77309980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2914 (or 2912 counting only the distinct ones).

The product of its (nonzero) digits is 95256, while the sum is 43.

The square root of 77309980 is about 8792.6093965330. The cubic root of 77309980 is about 426.0022114839.

The spelling of 77309980 in words is "seventy-seven million, three hundred nine thousand, nine hundred eighty".