77728697 has 4 divisors (see below), whose sum is σ = 77817216. Its totient is φ = 77640180.

The previous prime is 77728631. The next prime is 77728711. The reversal of 77728697 is 79682777.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 77728697 - 2¹⁰ = 77727673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77728397) 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, 42929 + ... + 44702.

It is an arithmetic number, because the mean of its divisors is an integer number (19454304).

Almost surely, 2^77728697 is an apocalyptic number.

It is an amenable number.

77728697 is a deficient number, since it is larger than the sum of its proper divisors (88519).

77728697 is an equidigital number, since it uses as much as digits as its factorization.

77728697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88518.

The product of its digits is 2074464, while the sum is 53.

The square root of 77728697 is about 8816.3879792123. The cubic root of 77728697 is about 426.7699144529.

The spelling of 77728697 in words is "seventy-seven million, seven hundred twenty-eight thousand, six hundred ninety-seven".