21499499522 has 6 divisors (see below), whose sum is σ = 32249560329. Its totient is φ = 10749646080.

The previous prime is 21499499467. The next prime is 21499499543. The reversal of 21499499522 is 22599499412.

It can be written as a sum of positive squares in 2 ways, for example, as 20209181281 + 1290318241 = 142159^2 + 35921^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=103681.

It is a Duffinian number.

It is an unprimeable number.

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 2 ways as a sum of consecutive naturals, for example, 155522 + ... + 259202.

Almost surely, 2^21499499522 is an apocalyptic number.

21499499522 is a deficient number, since it is larger than the sum of its proper divisors (10750060807).

21499499522 is an frugal number, since it uses more digits than its factorization.

21499499522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207364 (or 103683 counting only the distinct ones).

The product of its digits is 4199040, while the sum is 56.

The spelling of 21499499522 in words is "twenty-one billion, four hundred ninety-nine million, four hundred ninety-nine thousand, five hundred twenty-two".