20904351 has 16 divisors (see below), whose sum is σ = 31597440. Its totient is φ = 12186720.

The previous prime is 20904343. The next prime is 20904391. The reversal of 20904351 is 15340902.

It is not a de Polignac number, because 20904351 - 2³ = 20904343 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20904391) 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, 13365 + ... + 14846.

It is an arithmetic number, because the mean of its divisors is an integer number (1974840).

Almost surely, 2^20904351 is an apocalyptic number.

20904351 is a deficient number, since it is larger than the sum of its proper divisors (10693089).

20904351 is a wasteful number, since it uses less digits than its factorization.

20904351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28246.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 20904351 is about 4572.1276228907. The cubic root of 20904351 is about 275.4729097004.

It can be divided in two parts, 2090 and 4351, that added together give a triangular number (6441 = T₁₁₃).

The spelling of 20904351 in words is "twenty million, nine hundred four thousand, three hundred fifty-one".