21291038 has 8 divisors (see below), whose sum is σ = 33815232. Its totient is φ = 10019296.

The previous prime is 21291029. The next prime is 21291091. The reversal of 21291038 is 83019212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21290998 and 21291016.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 313070 + ... + 313137.

It is an arithmetic number, because the mean of its divisors is an integer number (4226904).

Almost surely, 2^21291038 is an apocalyptic number.

21291038 is a deficient number, since it is larger than the sum of its proper divisors (12524194).

21291038 is a wasteful number, since it uses less digits than its factorization.

21291038 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 626226.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 21291038 is about 4614.2212777456. The cubic root of 21291038 is about 277.1611013148.

The spelling of 21291038 in words is "twenty-one million, two hundred ninety-one thousand, thirty-eight".