77487780 has 48 divisors (see below), whose sum is σ = 218695680. Its totient is φ = 20498688.

The previous prime is 77487779. The next prime is 77487791. The reversal of 77487780 is 8778477.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2536 + ... + 12704.

It is an arithmetic number, because the mean of its divisors is an integer number (4556160).

Almost surely, 2^77487780 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 77487780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109347840).

77487780 is an abundant number, since it is smaller than the sum of its proper divisors (141207900).

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

77487780 is a wasteful number, since it uses less digits than its factorization.

77487780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10308 (or 10306 counting only the distinct ones).

The product of its (nonzero) digits is 614656, while the sum is 48.

The square root of 77487780 is about 8802.7143541069. The cubic root of 77487780 is about 426.3285393471.

The spelling of 77487780 in words is "seventy-seven million, four hundred eighty-seven thousand, seven hundred eighty".