71979769 has 4 divisors (see below), whose sum is σ = 74461860. Its totient is φ = 69497680.

The previous prime is 71979767. The next prime is 71979773. The reversal of 71979769 is 96797917.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 57577744 + 14402025 = 7588^2 + 3795^2 .

It is a cyclic number.

It is not a de Polignac number, because 71979769 - 2¹ = 71979767 is a prime.

It is a super-2 number, since 2×71979769² = 10362174290586722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71979767) 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 3 ways as a sum of consecutive naturals, for example, 1241002 + ... + 1241059.

It is an arithmetic number, because the mean of its divisors is an integer number (18615465).

Almost surely, 2^71979769 is an apocalyptic number.

It is an amenable number.

71979769 is a deficient number, since it is larger than the sum of its proper divisors (2482091).

71979769 is a wasteful number, since it uses less digits than its factorization.

71979769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2482090.

The product of its digits is 1500282, while the sum is 55.

The square root of 71979769 is about 8484.0891673768. The cubic root of 71979769 is about 415.9777959827.

The spelling of 71979769 in words is "seventy-one million, nine hundred seventy-nine thousand, seven hundred sixty-nine".