20104991531881 has 3 divisors (see below), whose sum is σ = 20104996015741. Its totient is φ = 20104987048022.

The previous prime is 20104991531813. The next prime is 20104991531903. The reversal of 20104991531881 is 18813519940102.

The square root of 20104991531881 is 4483859.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a de Polignac number, because none of the positive numbers 2^k-20104991531881 is a prime.

It is a super-2 number, since 2×20104991531881² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20104991531081) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2241930 + ... + 6725788.

Almost surely, 2^{20104991531881} is an apocalyptic number.

20104991531881 is the 4483859-th square number.

20104991531881 is the 2241930-th centered octagonal number.

It is an amenable number.

20104991531881 is a deficient number, since it is larger than the sum of its proper divisors (4483860).

20104991531881 is an frugal number, since it uses more digits than its factorization.

20104991531881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8967718 (or 4483859 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 52.

The spelling of 20104991531881 in words is "twenty trillion, one hundred four billion, nine hundred ninety-one million, five hundred thirty-one thousand, eight hundred eighty-one".