21890075099 has 2 divisors, whose sum is σ = 21890075100. Its totient is φ = 21890075098.

The previous prime is 21890075089. The next prime is 21890075101. The reversal of 21890075099 is 99057009812.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21890075099 is a prime.

It is a Sophie Germain prime.

Together with 21890075101, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21890075089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10945037549 + 10945037550.

It is an arithmetic number, because the mean of its divisors is an integer number (10945037550).

Almost surely, 2^21890075099 is an apocalyptic number.

21890075099 is a deficient number, since it is larger than the sum of its proper divisors (1).

21890075099 is an equidigital number, since it uses as much as digits as its factorization.

21890075099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 408240, while the sum is 50.

The spelling of 21890075099 in words is "twenty-one billion, eight hundred ninety million, seventy-five thousand, ninety-nine".