21322499 has 12 divisors (see below), whose sum is σ = 23553768. Its totient is φ = 19287840.

The previous prime is 21322493. The next prime is 21322547. The reversal of 21322499 is 99422312.

It is not a de Polignac number, because 21322499 - 2¹² = 21318403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21322493) 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 in 11 ways as a sum of consecutive naturals, for example, 37592 + ... + 38154.

It is an arithmetic number, because the mean of its divisors is an integer number (1962814).

Almost surely, 2^21322499 is an apocalyptic number.

21322499 is a deficient number, since it is larger than the sum of its proper divisors (2231269).

21322499 is a wasteful number, since it uses less digits than its factorization.

21322499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 898 (or 887 counting only the distinct ones).

The product of its digits is 7776, while the sum is 32.

The square root of 21322499 is about 4617.6291535809. The cubic root of 21322499 is about 277.2975511201.

The spelling of 21322499 in words is "twenty-one million, three hundred twenty-two thousand, four hundred ninety-nine".