21028290169 has 4 divisors (see below), whose sum is σ = 21188811600. Its totient is φ = 20867768740.

The previous prime is 21028290167. The next prime is 21028290181. The reversal of 21028290169 is 96109282012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21028290169 - 2¹ = 21028290167 is a prime.

It is a super-2 number, since 2×21028290169² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21028290161) 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, 80260519 + ... + 80260780.

It is an arithmetic number, because the mean of its divisors is an integer number (5297202900).

Almost surely, 2^21028290169 is an apocalyptic number.

It is an amenable number.

21028290169 is a deficient number, since it is larger than the sum of its proper divisors (160521431).

21028290169 is a wasteful number, since it uses less digits than its factorization.

21028290169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160521430.

The product of its (nonzero) digits is 31104, while the sum is 40.

The spelling of 21028290169 in words is "twenty-one billion, twenty-eight million, two hundred ninety thousand, one hundred sixty-nine".