20390855 has 8 divisors (see below), whose sum is σ = 24721872. Its totient is φ = 16144128.

The previous prime is 20390833. The next prime is 20390861. The reversal of 20390855 is 55809302.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20390855 - 2¹² = 20386759 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20537 + ... + 21506.

It is an arithmetic number, because the mean of its divisors is an integer number (3090234).

Almost surely, 2^20390855 is an apocalyptic number.

20390855 is a deficient number, since it is larger than the sum of its proper divisors (4331017).

20390855 is an equidigital number, since it uses as much as digits as its factorization.

20390855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42145.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 20390855 is about 4515.6234342558. The cubic root of 20390855 is about 273.1986058550.

The spelling of 20390855 in words is "twenty million, three hundred ninety thousand, eight hundred fifty-five".