20904243 has 8 divisors (see below), whose sum is σ = 27998208. Its totient is φ = 13873224.

The previous prime is 20904227. The next prime is 20904251. The reversal of 20904243 is 34240902.

It is a happy number.

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

It is not a de Polignac number, because 20904243 - 2⁴ = 20904227 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20904283) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14955 + ... + 16292.

It is an arithmetic number, because the mean of its divisors is an integer number (3499776).

Almost surely, 2^20904243 is an apocalyptic number.

20904243 is a deficient number, since it is larger than the sum of its proper divisors (7093965).

20904243 is a wasteful number, since it uses less digits than its factorization.

20904243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31473.

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 20904243 is about 4572.1158121815. The cubic root of 20904243 is about 275.4724352996.

The spelling of 20904243 in words is "twenty million, nine hundred four thousand, two hundred forty-three".