77131440 has 100 divisors (see below), whose sum is σ = 267911424. Its totient is φ = 20566656.

The previous prime is 77131423. The next prime is 77131451. The reversal of 77131440 is 4413177.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 529 + ... + 12431.

Almost surely, 2^77131440 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 77131440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133955712).

77131440 is an abundant number, since it is smaller than the sum of its proper divisors (190779984).

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

77131440 is a wasteful number, since it uses less digits than its factorization.

77131440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11928 (or 11913 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 77131440 is about 8782.4506830383. The cubic root of 77131440 is about 425.6740216005.

The spelling of 77131440 in words is "seventy-seven million, one hundred thirty-one thousand, four hundred forty".