77543640 has 48 divisors (see below), whose sum is σ = 252018000. Its totient is φ = 20678208.

The previous prime is 77543633. The next prime is 77543677. The reversal of 77543640 is 4634577.

77543640 is a `hidden beast` number, since 7 + 7 + 5 + 4 + 3 + 640 = 666.

It is a super-2 number, since 2×77543640² = 12026032208899200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 77543595 and 77543604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 107340 + ... + 108059.

It is an arithmetic number, because the mean of its divisors is an integer number (5250375).

Almost surely, 2^77543640 is an apocalyptic number.

It is an amenable number.

77543640 is an abundant number, since it is smaller than the sum of its proper divisors (174474360).

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

77543640 is a wasteful number, since it uses less digits than its factorization.

77543640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215416 (or 215409 counting only the distinct ones).

The product of its (nonzero) digits is 70560, while the sum is 36.

The square root of 77543640 is about 8805.8866674515. The cubic root of 77543640 is about 426.4309597628.

The spelling of 77543640 in words is "seventy-seven million, five hundred forty-three thousand, six hundred forty".