20761131891 has 16 divisors (see below), whose sum is σ = 28132958880. Its totient is φ = 13616006400.

The previous prime is 20761131863. The next prime is 20761131893. The reversal of 20761131891 is 19813116702.

It is not a de Polignac number, because 20761131891 - 2⁷ = 20761131763 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20761131893) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36660 + ... + 207041.

It is an arithmetic number, because the mean of its divisors is an integer number (1758309930).

Almost surely, 2^20761131891 is an apocalyptic number.

20761131891 is a deficient number, since it is larger than the sum of its proper divisors (7371826989).

20761131891 is a wasteful number, since it uses less digits than its factorization.

20761131891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244166.

The product of its (nonzero) digits is 18144, while the sum is 39.

The spelling of 20761131891 in words is "twenty billion, seven hundred sixty-one million, one hundred thirty-one thousand, eight hundred ninety-one".