979993621 has 4 divisors (see below), whose sum is σ = 980175532. Its totient is φ = 979811712.

The previous prime is 979993601. The next prime is 979993627. The reversal of 979993621 is 126399979.

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 770062500 + 209931121 = 27750^2 + 14489^2 .

It is a cyclic number.

It is not a de Polignac number, because 979993621 - 2⁵ = 979993589 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 (979993627) 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, 82620 + ... + 93733.

It is an arithmetic number, because the mean of its divisors is an integer number (245043883).

Almost surely, 2^979993621 is an apocalyptic number.

It is an amenable number.

979993621 is a deficient number, since it is larger than the sum of its proper divisors (181911).

979993621 is a wasteful number, since it uses less digits than its factorization.

979993621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181910.

The product of its digits is 1653372, while the sum is 55.

The square root of 979993621 is about 31304.8497999911. The cubic root of 979993621 is about 993.2862332091.

The spelling of 979993621 in words is "nine hundred seventy-nine million, nine hundred ninety-three thousand, six hundred twenty-one".