20404885 has 8 divisors (see below), whose sum is σ = 24549336. Its totient is φ = 16281600.

The previous prime is 20404883. The next prime is 20404889. The reversal of 20404885 is 58840402.

It can be written as a sum of positive squares in 4 ways, for example, as 9375844 + 11029041 = 3062^2 + 3321^2 .

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

It is not a de Polignac number, because 20404885 - 2¹ = 20404883 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 (20404883) 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, 3084 + ... + 7093.

It is an arithmetic number, because the mean of its divisors is an integer number (3068667).

Almost surely, 2^20404885 is an apocalyptic number.

It is an amenable number.

20404885 is a deficient number, since it is larger than the sum of its proper divisors (4144451).

20404885 is a wasteful number, since it uses less digits than its factorization.

20404885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10583.

The product of its (nonzero) digits is 10240, while the sum is 31.

The square root of 20404885 is about 4517.1766624740. The cubic root of 20404885 is about 273.2612499125.

The spelling of 20404885 in words is "twenty million, four hundred four thousand, eight hundred eighty-five".