879691921 has 4 divisors (see below), whose sum is σ = 888401844. Its totient is φ = 870982000.

The previous prime is 879691913. The next prime is 879691949. The reversal of 879691921 is 129196978.

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 623051521 + 256640400 = 24961^2 + 16020^2 .

It is a cyclic number.

It is not a de Polignac number, because 879691921 - 2³ = 879691913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (879691951) 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, 4354810 + ... + 4355011.

It is an arithmetic number, because the mean of its divisors is an integer number (222100461).

Almost surely, 2^879691921 is an apocalyptic number.

It is an amenable number.

879691921 is a deficient number, since it is larger than the sum of its proper divisors (8709923).

879691921 is a wasteful number, since it uses less digits than its factorization.

879691921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8709922.

The product of its digits is 489888, while the sum is 52.

The square root of 879691921 is about 29659.6008233422. The cubic root of 879691921 is about 958.1721298874.

The spelling of 879691921 in words is "eight hundred seventy-nine million, six hundred ninety-one thousand, nine hundred twenty-one".