77400840 has 128 divisors (see below), whose sum is σ = 255467520. Its totient is φ = 18604800.

The previous prime is 77400839. The next prime is 77400877. The reversal of 77400840 is 4800477.

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

It is a junction number, because it is equal to n+sod(n) for n = 77400798 and 77400807.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 251967 + ... + 252273.

It is an arithmetic number, because the mean of its divisors is an integer number (1995840).

Almost surely, 2^77400840 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 77400840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127733760).

77400840 is an abundant number, since it is smaller than the sum of its proper divisors (178066680).

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

77400840 is a wasteful number, since it uses less digits than its factorization.

77400840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523 (or 519 counting only the distinct ones).

The product of its (nonzero) digits is 6272, while the sum is 30.

The square root of 77400840 is about 8797.7747186433. The cubic root of 77400840 is about 426.1690351691.

The spelling of 77400840 in words is "seventy-seven million, four hundred thousand, eight hundred forty".