78720780 has 48 divisors (see below), whose sum is σ = 227533824. Its totient is φ = 20314560.

The previous prime is 78720757. The next prime is 78720787. The reversal of 78720780 is 8702787.

It is a super-2 number, since 2×78720780² = 12393922407616800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78720787) 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, 19302 + ... + 23021.

It is an arithmetic number, because the mean of its divisors is an integer number (4740288).

Almost surely, 2^78720780 is an apocalyptic number.

It is an amenable number.

78720780 is an abundant number, since it is smaller than the sum of its proper divisors (148813044).

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

78720780 is a wasteful number, since it uses less digits than its factorization.

78720780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42366 (or 42364 counting only the distinct ones).

The product of its (nonzero) digits is 43904, while the sum is 39.

The square root of 78720780 is about 8872.4731614133. The cubic root of 78720780 is about 428.5779233936.

The spelling of 78720780 in words is "seventy-eight million, seven hundred twenty thousand, seven hundred eighty".