20906655 has 64 divisors (see below), whose sum is σ = 43573248. Its totient is φ = 8300160.

The previous prime is 20906647. The next prime is 20906687. The reversal of 20906655 is 55660902.

It is not a de Polignac number, because 20906655 - 2³ = 20906647 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 26172 + ... + 26958.

It is an arithmetic number, because the mean of its divisors is an integer number (680832).

Almost surely, 2^20906655 is an apocalyptic number.

20906655 is an abundant number, since it is smaller than the sum of its proper divisors (22666593).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20906655 is a wasteful number, since it uses less digits than its factorization.

20906655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 836.

The product of its (nonzero) digits is 16200, while the sum is 33.

The square root of 20906655 is about 4572.3795774192. The cubic root of 20906655 is about 275.4830298626.

The spelling of 20906655 in words is "twenty million, nine hundred six thousand, six hundred fifty-five".