77643472 has 20 divisors (see below), whose sum is σ = 150637060. Its totient is φ = 38769408.

The previous prime is 77643451. The next prime is 77643473. The reversal of 77643472 is 27434677.

It can be written as a sum of positive squares in 2 ways, for example, as 39992976 + 37650496 = 6324^2 + 6136^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77643473) 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, 10804 + ... + 16492.

It is an arithmetic number, because the mean of its divisors is an integer number (7531853).

Almost surely, 2^77643472 is an apocalyptic number.

It is an amenable number.

77643472 is a deficient number, since it is larger than the sum of its proper divisors (72993588).

77643472 is a wasteful number, since it uses less digits than its factorization.

77643472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6550 (or 6544 counting only the distinct ones).

The product of its digits is 197568, while the sum is 40.

The square root of 77643472 is about 8811.5533250387. The cubic root of 77643472 is about 426.6138812737.

It can be divided in two parts, 7764 and 3472, that added together give a square (11236 = 106²).

The spelling of 77643472 in words is "seventy-seven million, six hundred forty-three thousand, four hundred seventy-two".