20156173 has 4 divisors (see below), whose sum is σ = 20351968. Its totient is φ = 19960380.

The previous prime is 20156153. The next prime is 20156177. The reversal of 20156173 is 37165102.

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 20156173 - 2²¹ = 18059021 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 (20156177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 97743 + ... + 97948.

It is an arithmetic number, because the mean of its divisors is an integer number (5087992).

Almost surely, 2^20156173 is an apocalyptic number.

It is an amenable number.

20156173 is a deficient number, since it is larger than the sum of its proper divisors (195795).

20156173 is a wasteful number, since it uses less digits than its factorization.

20156173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195794.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 20156173 is about 4489.5626735797. The cubic root of 20156173 is about 272.1464618151.

The spelling of 20156173 in words is "twenty million, one hundred fifty-six thousand, one hundred seventy-three".