21292169 has 4 divisors (see below), whose sum is σ = 21487620. Its totient is φ = 21096720.

The previous prime is 21292163. The next prime is 21292171. The reversal of 21292169 is 96129212.

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 6943225 + 14348944 = 2635^2 + 3788^2 .

It is a cyclic number.

It is not a de Polignac number, because 21292169 - 2⁴ = 21292153 is a prime.

It is a super-2 number, since 2×21292169² = 906712921449122, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21292163) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 97562 + ... + 97779.

It is an arithmetic number, because the mean of its divisors is an integer number (5371905).

Almost surely, 2^21292169 is an apocalyptic number.

It is an amenable number.

21292169 is a deficient number, since it is larger than the sum of its proper divisors (195451).

21292169 is a wasteful number, since it uses less digits than its factorization.

21292169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195450.

The product of its digits is 3888, while the sum is 32.

The square root of 21292169 is about 4614.3438320091. The cubic root of 21292169 is about 277.1660089142.

The spelling of 21292169 in words is "twenty-one million, two hundred ninety-two thousand, one hundred sixty-nine".