71979819 has 8 divisors (see below), whose sum is σ = 101618640. Its totient is φ = 45163776.

The previous prime is 71979779. The next prime is 71979829. The reversal of 71979819 is 91897917.

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

It is a de Polignac number, because none of the positive numbers 2^k-71979819 is a prime.

It is a super-2 number, since 2×71979819² = 10362188686545522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51), and also a Moran number because the ratio is a prime number: 1411369 = 71979819 / (7 + 1 + 9 + 7 + 9 + 8 + 1 + 9).

It is not an unprimeable number, because it can be changed into a prime (71979829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 705634 + ... + 705735.

It is an arithmetic number, because the mean of its divisors is an integer number (12702330).

Almost surely, 2^71979819 is an apocalyptic number.

71979819 is a deficient number, since it is larger than the sum of its proper divisors (29638821).

71979819 is a wasteful number, since it uses less digits than its factorization.

71979819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1411389.

The product of its digits is 285768, while the sum is 51.

The square root of 71979819 is about 8484.0921140685. The cubic root of 71979819 is about 415.9778923009.

The spelling of 71979819 in words is "seventy-one million, nine hundred seventy-nine thousand, eight hundred nineteen".