21936120931 has 4 divisors (see below), whose sum is σ = 21936586000. Its totient is φ = 21935655864.

The previous prime is 21936120917. The next prime is 21936120937. The reversal of 21936120931 is 13902163912.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21936120931 - 2³³ = 13346186339 is a prime.

It is a super-2 number, since 2×21936120931² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21936120937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 152631 + ... + 259168.

It is an arithmetic number, because the mean of its divisors is an integer number (5484146500).

Almost surely, 2^21936120931 is an apocalyptic number.

21936120931 is a deficient number, since it is larger than the sum of its proper divisors (465069).

21936120931 is an equidigital number, since it uses as much as digits as its factorization.

21936120931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465068.

The product of its (nonzero) digits is 17496, while the sum is 37.

The spelling of 21936120931 in words is "twenty-one billion, nine hundred thirty-six million, one hundred twenty thousand, nine hundred thirty-one".