77231280 has 80 divisors (see below), whose sum is σ = 273625344. Its totient is φ = 17652480.

The previous prime is 77231267. The next prime is 77231281. The reversal of 77231280 is 8213277.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×77231280² = 11929341220876800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (77231281) 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, 21306 + ... + 24665.

Almost surely, 2^77231280 is an apocalyptic number.

77231280 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

77231280 is an abundant number, since it is smaller than the sum of its proper divisors (196394064).

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

77231280 is a wasteful number, since it uses less digits than its factorization.

77231280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45994 (or 45988 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 30.

The square root of 77231280 is about 8788.1329075066. The cubic root of 77231280 is about 425.8576085194.

The spelling of 77231280 in words is "seventy-seven million, two hundred thirty-one thousand, two hundred eighty".