21012023099 has 2 divisors, whose sum is σ = 21012023100. Its totient is φ = 21012023098.

The previous prime is 21012023093. The next prime is 21012023111. The reversal of 21012023099 is 99032021012.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21012023099 is a prime.

It is a super-2 number, since 2×21012023099² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21012023093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506011549 + 10506011550.

It is an arithmetic number, because the mean of its divisors is an integer number (10506011550).

Almost surely, 2^21012023099 is an apocalyptic number.

21012023099 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012023099 is an equidigital number, since it uses as much as digits as its factorization.

21012023099 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 29.

The spelling of 21012023099 in words is "twenty-one billion, twelve million, twenty-three thousand, ninety-nine".