72779421 has 16 divisors (see below), whose sum is σ = 114004800. Its totient is φ = 40715520.

The previous prime is 72779419. The next prime is 72779437. The reversal of 72779421 is 12497727.

It is not a de Polignac number, because 72779421 - 2¹ = 72779419 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 72779421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72779401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 84396 + ... + 85253.

It is an arithmetic number, because the mean of its divisors is an integer number (7125300).

Almost surely, 2^72779421 is an apocalyptic number.

It is an amenable number.

72779421 is a deficient number, since it is larger than the sum of its proper divisors (41225379).

72779421 is a wasteful number, since it uses less digits than its factorization.

72779421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169676.

The product of its digits is 49392, while the sum is 39.

The square root of 72779421 is about 8531.0855698440. The cubic root of 72779421 is about 417.5125477004.

The spelling of 72779421 in words is "seventy-two million, seven hundred seventy-nine thousand, four hundred twenty-one".