21026995 has 16 divisors (see below), whose sum is σ = 27620352. Its totient is φ = 15240160.

The previous prime is 21026987. The next prime is 21027007. The reversal of 21026995 is 59962012.

It is not a de Polignac number, because 21026995 - 2³ = 21026987 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21026995.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 23934 + ... + 24796.

It is an arithmetic number, because the mean of its divisors is an integer number (1726272).

Almost surely, 2^21026995 is an apocalyptic number.

21026995 is a deficient number, since it is larger than the sum of its proper divisors (6593357).

21026995 is a wasteful number, since it uses less digits than its factorization.

21026995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1322.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 21026995 is about 4585.5201449781. The cubic root of 21026995 is about 276.0105847302.

The spelling of 21026995 in words is "twenty-one million, twenty-six thousand, nine hundred ninety-five".