20079891 has 24 divisors (see below), whose sum is σ = 31676736. Its totient is φ = 12182400.

The previous prime is 20079887. The next prime is 20079893. The reversal of 20079891 is 19897002.

It is a happy number.

It is not a de Polignac number, because 20079891 - 2² = 20079887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20079893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7366 + ... + 9716.

It is an arithmetic number, because the mean of its divisors is an integer number (1319864).

Almost surely, 2^20079891 is an apocalyptic number.

20079891 is a deficient number, since it is larger than the sum of its proper divisors (11596845).

20079891 is a wasteful number, since it uses less digits than its factorization.

20079891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2443 (or 2440 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 20079891 is about 4481.0591381949. The cubic root of 20079891 is about 271.8027107053.

The spelling of 20079891 in words is "twenty million, seventy-nine thousand, eight hundred ninety-one".