20972842 has 16 divisors (see below), whose sum is σ = 34968672. Its totient is φ = 9352720.

The previous prime is 20972839. The next prime is 20972851. The reversal of 20972842 is 24827902.

It is a junction number, because it is equal to n+sod(n) for n = 20972798 and 20972807.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7828 + ... + 10159.

It is an arithmetic number, because the mean of its divisors is an integer number (2185542).

Almost surely, 2^20972842 is an apocalyptic number.

20972842 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

20972842 is a deficient number, since it is larger than the sum of its proper divisors (13995830).

20972842 is a wasteful number, since it uses less digits than its factorization.

20972842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18053.

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 20972842 is about 4579.6115555798. The cubic root of 20972842 is about 275.7734348041.

The spelling of 20972842 in words is "twenty million, nine hundred seventy-two thousand, eight hundred forty-two".