20131991793 has 24 divisors (see below), whose sum is σ = 30638504832. Its totient is φ = 12713139648.

The previous prime is 20131991771. The next prime is 20131991801. The reversal of 20131991793 is 39719913102.

It is not a de Polignac number, because 20131991793 - 2¹³ = 20131983601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20131991393) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 450796 + ... + 493437.

It is an arithmetic number, because the mean of its divisors is an integer number (1276604368).

Almost surely, 2^20131991793 is an apocalyptic number.

20131991793 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

20131991793 is a deficient number, since it is larger than the sum of its proper divisors (10506513039).

20131991793 is a wasteful number, since it uses less digits than its factorization.

20131991793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 944365 (or 944362 counting only the distinct ones).

The product of its (nonzero) digits is 91854, while the sum is 45.

The spelling of 20131991793 in words is "twenty billion, one hundred thirty-one million, nine hundred ninety-one thousand, seven hundred ninety-three".