20999995 has 16 divisors (see below), whose sum is σ = 26127360. Its totient is φ = 16192000.

The previous prime is 20999977. The next prime is 20999999. The reversal of 20999995 is 59999902.

It is not a de Polignac number, because 20999995 - 2¹⁵ = 20967227 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20999999) 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 15 ways as a sum of consecutive naturals, for example, 17670 + ... + 18820.

It is an arithmetic number, because the mean of its divisors is an integer number (1632960).

Almost surely, 2^20999995 is an apocalyptic number.

20999995 is a deficient number, since it is larger than the sum of its proper divisors (5127365).

20999995 is a wasteful number, since it uses less digits than its factorization.

20999995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1286.

The product of its (nonzero) digits is 590490, while the sum is 52.

The square root of 20999995 is about 4582.5751494111. The cubic root of 20999995 is about 275.8923957419.

The spelling of 20999995 in words is "twenty million, nine hundred ninety-nine thousand, nine hundred ninety-five".