72797779 has 4 divisors (see below), whose sum is σ = 74171376. Its totient is φ = 71424184.

The previous prime is 72797761. The next prime is 72797807. The reversal of 72797779 is 97779727.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97779727 = 83 ⋅1178069.

It is a cyclic number.

It is not a de Polignac number, because 72797779 - 2¹⁷ = 72666707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72797749) 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, 686719 + ... + 686824.

It is an arithmetic number, because the mean of its divisors is an integer number (18542844).

Almost surely, 2^72797779 is an apocalyptic number.

72797779 is a deficient number, since it is larger than the sum of its proper divisors (1373597).

72797779 is a wasteful number, since it uses less digits than its factorization.

72797779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1373596.

The product of its digits is 2722734, while the sum is 55.

The square root of 72797779 is about 8532.1614494804. The cubic root of 72797779 is about 417.5476494314.

The spelling of 72797779 in words is "seventy-two million, seven hundred ninety-seven thousand, seven hundred seventy-nine".