21023099 has 2 divisors, whose sum is σ = 21023100. Its totient is φ = 21023098.

The previous prime is 21023089. The next prime is 21023111. The reversal of 21023099 is 99032012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21023099 - 2⁴ = 21023083 is a prime.

It is not a weakly prime, because it can be changed into another prime (21023089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10511549 + 10511550.

It is an arithmetic number, because the mean of its divisors is an integer number (10511550).

Almost surely, 2^21023099 is an apocalyptic number.

21023099 is a deficient number, since it is larger than the sum of its proper divisors (1).

21023099 is an equidigital number, since it uses as much as digits as its factorization.

21023099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 21023099 is about 4585.0953098055. The cubic root of 21023099 is about 275.9935367457.

The spelling of 21023099 in words is "twenty-one million, twenty-three thousand, ninety-nine".