21001295 has 16 divisors (see below), whose sum is σ = 28960320. Its totient is φ = 14321664.

The previous prime is 21001247. The next prime is 21001319. The reversal of 21001295 is 59210012.

It is not a de Polignac number, because 21001295 - 2¹⁸ = 20739151 is a prime.

It is a congruent number.

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, 5201 + ... + 8309.

It is an arithmetic number, because the mean of its divisors is an integer number (1810020).

Almost surely, 2^21001295 is an apocalyptic number.

21001295 is a deficient number, since it is larger than the sum of its proper divisors (7959025).

21001295 is a wasteful number, since it uses less digits than its factorization.

21001295 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3314.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 21001295 is about 4582.7169888615. The cubic root of 21001295 is about 275.8980886435.

The spelling of 21001295 in words is "twenty-one million, one thousand, two hundred ninety-five".