21369942529 has 4 divisors (see below), whose sum is σ = 23013784276. Its totient is φ = 19726100784.

The previous prime is 21369942527. The next prime is 21369942541. The reversal of 21369942529 is 92524996312.

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 8515598400 + 12854344129 = 92280^2 + 113377^2 .

It is not a de Polignac number, because 21369942529 - 2¹ = 21369942527 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21369942527) 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 3 ways as a sum of consecutive naturals, for example, 821920854 + ... + 821920879.

It is an arithmetic number, because the mean of its divisors is an integer number (5753446069).

Almost surely, 2^21369942529 is an apocalyptic number.

It is an amenable number.

21369942529 is a deficient number, since it is larger than the sum of its proper divisors (1643841747).

21369942529 is a wasteful number, since it uses less digits than its factorization.

21369942529 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1643841746.

The product of its digits is 2099520, while the sum is 52.

The spelling of 21369942529 in words is "twenty-one billion, three hundred sixty-nine million, nine hundred forty-two thousand, five hundred twenty-nine".