77436820 has 12 divisors (see below), whose sum is σ = 162617364. Its totient is φ = 30974720.

The previous prime is 77436809. The next prime is 77436829. The reversal of 77436820 is 2863477.

It can be written as a sum of positive squares in 2 ways, for example, as 50438404 + 26998416 = 7102^2 + 5196^2 .

It is a super-2 number, since 2×77436820² = 11992922183424800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 77436820.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77436829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1935901 + ... + 1935940.

It is an arithmetic number, because the mean of its divisors is an integer number (13551447).

Almost surely, 2^77436820 is an apocalyptic number.

It is an amenable number.

77436820 is an abundant number, since it is smaller than the sum of its proper divisors (85180544).

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

77436820 is a wasteful number, since it uses less digits than its factorization.

77436820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3871850 (or 3871848 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 37.

The square root of 77436820 is about 8799.8193163269. The cubic root of 77436820 is about 426.2350602344.

The spelling of 77436820 in words is "seventy-seven million, four hundred thirty-six thousand, eight hundred twenty".