20906118990 has 48 divisors (see below), whose sum is σ = 54481544208. Its totient is φ = 5562079488.

The previous prime is 20906118979. The next prime is 20906119067. The reversal of 20906118990 is 9981160902.

20906118990 is a `hidden beast` number, since 20 + 9 + 0 + 611 + 8 + 9 + 9 + 0 = 666.

It is a super-2 number, since 2×20906118990² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 229264 + ... + 307203.

It is an arithmetic number, because the mean of its divisors is an integer number (1135032171).

Almost surely, 2^20906118990 is an apocalyptic number.

20906118990 is an abundant number, since it is smaller than the sum of its proper divisors (33575425218).

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

20906118990 is a wasteful number, since it uses less digits than its factorization.

20906118990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 536913 (or 536910 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 45.

It can be divided in two parts, 2090611 and 8990, that added together give a square (2099601 = 1449²).

The spelling of 20906118990 in words is "twenty billion, nine hundred six million, one hundred eighteen thousand, nine hundred ninety".