20491072680186 has 96 divisors (see below), whose sum is σ = 45072718411968. Its totient is φ = 6727361921280.

The previous prime is 20491072680179. The next prime is 20491072680187. The reversal of 20491072680186 is 68108627019402.

It is a happy number.

20491072680186 is a `hidden beast` number, since 2 + 0 + 491 + 0 + 72 + 6 + 8 + 0 + 1 + 86 = 666.

It is a super-2 number, since 2×20491072680186² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20491072680187) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 264392901 + ... + 264470391.

It is an arithmetic number, because the mean of its divisors is an integer number (469507483458).

Almost surely, 2^{20491072680186} is an apocalyptic number.

20491072680186 is an abundant number, since it is smaller than the sum of its proper divisors (24581645731782).

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

20491072680186 is a wasteful number, since it uses less digits than its factorization.

20491072680186 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78476 (or 78473 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 54.

Adding to 20491072680186 its reverse (68108627019402), we get a palindrome (88599699699588).

The spelling of 20491072680186 in words is "twenty trillion, four hundred ninety-one billion, seventy-two million, six hundred eighty thousand, one hundred eighty-six".