21065023 has 16 divisors (see below), whose sum is σ = 25634880. Its totient is φ = 16897536.

The previous prime is 21065003. The next prime is 21065041. The reversal of 21065023 is 32056012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21065023 - 2¹³ = 21056831 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21065003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26865 + ... + 27637.

It is an arithmetic number, because the mean of its divisors is an integer number (1602180).

Almost surely, 2^21065023 is an apocalyptic number.

21065023 is a deficient number, since it is larger than the sum of its proper divisors (4569857).

21065023 is a wasteful number, since it uses less digits than its factorization.

21065023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1026.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 21065023 is about 4589.6648025755. The cubic root of 21065023 is about 276.1768758770.

The spelling of 21065023 in words is "twenty-one million, sixty-five thousand, twenty-three".