21498798829 has 4 divisors (see below), whose sum is σ = 22079847484. Its totient is φ = 20917750176.

The previous prime is 21498798823. The next prime is 21498798833. The reversal of 21498798829 is 92889789412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20477037604 + 1021761225 = 143098^2 + 31965^2 .

It is a cyclic number.

It is not a de Polignac number, because 21498798829 - 2¹⁹ = 21498274541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21498798823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 290524272 + ... + 290524345.

It is an arithmetic number, because the mean of its divisors is an integer number (5519961871).

Almost surely, 2^21498798829 is an apocalyptic number.

It is an amenable number.

21498798829 is a deficient number, since it is larger than the sum of its proper divisors (581048655).

21498798829 is an equidigital number, since it uses as much as digits as its factorization.

21498798829 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 581048654.

The product of its digits is 41803776, while the sum is 67.

The spelling of 21498798829 in words is "twenty-one billion, four hundred ninety-eight million, seven hundred ninety-eight thousand, eight hundred twenty-nine".