21040499 has 2 divisors, whose sum is σ = 21040500. Its totient is φ = 21040498.

The previous prime is 21040493. The next prime is 21040511. The reversal of 21040499 is 99404012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21040499 - 2²⁴ = 4263283 is a prime.

It is a Chen prime.

It is a plaindrome in base 13.

It is not a weakly prime, because it can be changed into another prime (21040493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10520249 + 10520250.

It is an arithmetic number, because the mean of its divisors is an integer number (10520250).

Almost surely, 2^21040499 is an apocalyptic number.

21040499 is a deficient number, since it is larger than the sum of its proper divisors (1).

21040499 is an equidigital number, since it uses as much as digits as its factorization.

21040499 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 21040499 is about 4586.9923697342. The cubic root of 21040499 is about 276.0696587811.

The spelling of 21040499 in words is "twenty-one million, forty thousand, four hundred ninety-nine".