77742728 has 32 divisors (see below), whose sum is σ = 168946560. Its totient is φ = 32847360.

The previous prime is 77742727. The next prime is 77742779. The reversal of 77742728 is 82724777.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (77742727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5801 + ... + 13752.

It is an arithmetic number, because the mean of its divisors is an integer number (5279580).

Almost surely, 2^77742728 is an apocalyptic number.

It is an amenable number.

77742728 is an abundant number, since it is smaller than the sum of its proper divisors (91203832).

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

77742728 is a wasteful number, since it uses less digits than its factorization.

77742728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19637 (or 19633 counting only the distinct ones).

The product of its digits is 307328, while the sum is 44.

The square root of 77742728 is about 8817.1836773428. The cubic root of 77742728 is about 426.7955920067.

The spelling of 77742728 in words is "seventy-seven million, seven hundred forty-two thousand, seven hundred twenty-eight".