77728553 has 12 divisors (see below), whose sum is σ = 92345472. Its totient is φ = 65205000.

The previous prime is 77728537. The next prime is 77728559. The reversal of 77728553 is 35582777.

It is not a de Polignac number, because 77728553 - 2⁴ = 77728537 is a prime.

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 Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77728559) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14573 + ... + 19178.

It is an arithmetic number, because the mean of its divisors is an integer number (7695456).

Almost surely, 2^77728553 is an apocalyptic number.

It is an amenable number.

77728553 is a deficient number, since it is larger than the sum of its proper divisors (14616919).

77728553 is a wasteful number, since it uses less digits than its factorization.

77728553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33812 (or 33805 counting only the distinct ones).

The product of its digits is 411600, while the sum is 44.

The square root of 77728553 is about 8816.3798125988. The cubic root of 77728553 is about 426.7696509085.

The spelling of 77728553 in words is "seventy-seven million, seven hundred twenty-eight thousand, five hundred fifty-three".