21102123019 has 2 divisors, whose sum is σ = 21102123020. Its totient is φ = 21102123018.

The previous prime is 21102122983. The next prime is 21102123047. The reversal of 21102123019 is 91032120112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21102123019 - 2¹⁷ = 21101991947 is a prime.

It is a super-2 number, since 2×21102123019² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21102123059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551061509 + 10551061510.

It is an arithmetic number, because the mean of its divisors is an integer number (10551061510).

Almost surely, 2^21102123019 is an apocalyptic number.

21102123019 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102123019 is an equidigital number, since it uses as much as digits as its factorization.

21102123019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 22.

The spelling of 21102123019 in words is "twenty-one billion, one hundred two million, one hundred twenty-three thousand, nineteen".