72179861 has 8 divisors (see below), whose sum is σ = 77888664. Its totient is φ = 66493440.

The previous prime is 72179839. The next prime is 72179881. The reversal of 72179861 is 16897127.

It can be written as a sum of positive squares in 4 ways, for example, as 2540836 + 69639025 = 1594^2 + 8345^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 72179861 - 2¹⁰ = 72178837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72179881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1445 + ... + 12101.

It is an arithmetic number, because the mean of its divisors is an integer number (9736083).

Almost surely, 2^72179861 is an apocalyptic number.

It is an amenable number.

72179861 is a deficient number, since it is larger than the sum of its proper divisors (5708803).

72179861 is a wasteful number, since it uses less digits than its factorization.

72179861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11191.

The product of its digits is 42336, while the sum is 41.

The square root of 72179861 is about 8495.8731746655. The cubic root of 72179861 is about 416.3628894782.

The spelling of 72179861 in words is "seventy-two million, one hundred seventy-nine thousand, eight hundred sixty-one".