79666989 has 4 divisors (see below), whose sum is σ = 106222656. Its totient is φ = 53111324.

The previous prime is 79666919. The next prime is 79666991. The reversal of 79666989 is 98966697.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 79666989 - 2⁷ = 79666861 is a prime.

It is a super-2 number, since 2×79666989² = 12693658272652242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79666919) 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, 13277829 + ... + 13277834.

It is an arithmetic number, because the mean of its divisors is an integer number (26555664).

Almost surely, 2^79666989 is an apocalyptic number.

It is an amenable number.

79666989 is a deficient number, since it is larger than the sum of its proper divisors (26555667).

79666989 is a wasteful number, since it uses less digits than its factorization.

79666989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26555666.

The product of its digits is 8817984, while the sum is 60.

The square root of 79666989 is about 8925.6366159507. The cubic root of 79666989 is about 430.2882311276.

The spelling of 79666989 in words is "seventy-nine million, six hundred sixty-six thousand, nine hundred eighty-nine".