20979895 has 8 divisors (see below), whose sum is σ = 26501040. Its totient is φ = 15900480.

The previous prime is 20979877. The next prime is 20979899. The reversal of 20979895 is 59897902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20979895 - 2¹⁷ = 20848823 is a prime.

It is a super-2 number, since 2×20979895² = 880311988422050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20979899) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 110326 + ... + 110515.

It is an arithmetic number, because the mean of its divisors is an integer number (3312630).

Almost surely, 2^20979895 is an apocalyptic number.

20979895 is a deficient number, since it is larger than the sum of its proper divisors (5521145).

20979895 is a wasteful number, since it uses less digits than its factorization.

20979895 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220865.

The product of its (nonzero) digits is 408240, while the sum is 49.

The square root of 20979895 is about 4580.3815343266. The cubic root of 20979895 is about 275.8043448105.

The spelling of 20979895 in words is "twenty million, nine hundred seventy-nine thousand, eight hundred ninety-five".