20904657 has 8 divisors (see below), whose sum is σ = 27996576. Its totient is φ = 13874592.

The previous prime is 20904649. The next prime is 20904673. The reversal of 20904657 is 75640902.

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

It is not a de Polignac number, because 20904657 - 2³ = 20904649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20904647) 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, 14668 + ... + 16029.

It is an arithmetic number, because the mean of its divisors is an integer number (3499572).

Almost surely, 2^20904657 is an apocalyptic number.

It is an amenable number.

20904657 is a deficient number, since it is larger than the sum of its proper divisors (7091919).

20904657 is a wasteful number, since it uses less digits than its factorization.

20904657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30927.

The product of its (nonzero) digits is 15120, while the sum is 33.

The square root of 20904657 is about 4572.1610864010. The cubic root of 20904657 is about 275.4742538273.

The spelling of 20904657 in words is "twenty million, nine hundred four thousand, six hundred fifty-seven".