21998746529 has 8 divisors (see below), whose sum is σ = 22963691688. Its totient is φ = 21053295360.

The previous prime is 21998746519. The next prime is 21998746547. The reversal of 21998746529 is 92564789912.

It can be written as a sum of positive squares in 4 ways, for example, as 5390496400 + 16608250129 = 73420^2 + 128873^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21998746529 - 2²⁸ = 21730311073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21998746519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4871192 + ... + 4875705.

It is an arithmetic number, because the mean of its divisors is an integer number (2870461461).

Almost surely, 2^21998746529 is an apocalyptic number.

It is an amenable number.

21998746529 is a deficient number, since it is larger than the sum of its proper divisors (964945159).

21998746529 is an equidigital number, since it uses as much as digits as its factorization.

21998746529 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9746995.

The product of its digits is 19595520, while the sum is 62.

The spelling of 21998746529 in words is "twenty-one billion, nine hundred ninety-eight million, seven hundred forty-six thousand, five hundred twenty-nine".