21312115933 has 2 divisors, whose sum is σ = 21312115934. Its totient is φ = 21312115932.

The previous prime is 21312115907. The next prime is 21312115963. The reversal of 21312115933 is 33951121312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20903954724 + 408161209 = 144582^2 + 20203^2 .

It is a cyclic number.

It is not a de Polignac number, because 21312115933 - 2⁹ = 21312115421 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21312115895 and 21312115904.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21312115963) 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 as a sum of consecutive naturals, namely, 10656057966 + 10656057967.

It is an arithmetic number, because the mean of its divisors is an integer number (10656057967).

Almost surely, 2^21312115933 is an apocalyptic number.

It is an amenable number.

21312115933 is a deficient number, since it is larger than the sum of its proper divisors (1).

21312115933 is an equidigital number, since it uses as much as digits as its factorization.

21312115933 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4860, while the sum is 31.

The spelling of 21312115933 in words is "twenty-one billion, three hundred twelve million, one hundred fifteen thousand, nine hundred thirty-three".