20215169 has 4 divisors (see below), whose sum is σ = 21770196. Its totient is φ = 18660144.

The previous prime is 20215147. The next prime is 20215171. The reversal of 20215169 is 96151202.

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 13965169 + 6250000 = 3737^2 + 2500^2 .

It is a cyclic number.

It is not a de Polignac number, because 20215169 - 2²⁴ = 3437953 is a prime.

It is a super-2 number, since 2×20215169² = 817306115397122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20215109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 777494 + ... + 777519.

It is an arithmetic number, because the mean of its divisors is an integer number (5442549).

Almost surely, 2^20215169 is an apocalyptic number.

It is an amenable number.

20215169 is a deficient number, since it is larger than the sum of its proper divisors (1555027).

20215169 is a wasteful number, since it uses less digits than its factorization.

20215169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1555026.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 20215169 is about 4496.1282232605. The cubic root of 20215169 is about 272.4117223801.

The spelling of 20215169 in words is "twenty million, two hundred fifteen thousand, one hundred sixty-nine".