21370499 has 2 divisors, whose sum is σ = 21370500. Its totient is φ = 21370498.

The previous prime is 21370483. The next prime is 21370511. The reversal of 21370499 is 99407312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21370499 - 2⁴ = 21370483 is a prime.

It is not a weakly prime, because it can be changed into another prime (21370409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10685249 + 10685250.

It is an arithmetic number, because the mean of its divisors is an integer number (10685250).

Almost surely, 2^21370499 is an apocalyptic number.

21370499 is a deficient number, since it is larger than the sum of its proper divisors (1).

21370499 is an equidigital number, since it uses as much as digits as its factorization.

21370499 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 21370499 is about 4622.8237041877. The cubic root of 21370499 is about 277.5054740148.

The spelling of 21370499 in words is "twenty-one million, three hundred seventy thousand, four hundred ninety-nine".