77973840 has 280 divisors, whose sum is σ = 312265728. Its totient is φ = 17729280.

The previous prime is 77973839. The next prime is 77973859. The reversal of 77973840 is 4837977.

It is a tau number, because it is divible by the number of its divisors (280).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 408145 + ... + 408335.

Almost surely, 2^77973840 is an apocalyptic number.

77973840 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77973840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156132864).

77973840 is an abundant number, since it is smaller than the sum of its proper divisors (234291888).

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

77973840 is a wasteful number, since it uses less digits than its factorization.

77973840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229 (or 208 counting only the distinct ones).

The product of its (nonzero) digits is 296352, while the sum is 45.

The square root of 77973840 is about 8830.2797237687. The cubic root of 77973840 is about 427.2180966958.

The spelling of 77973840 in words is "seventy-seven million, nine hundred seventy-three thousand, eight hundred forty".