2157945173 has 4 divisors (see below), whose sum is σ = 2158116588. Its totient is φ = 2157773760.

The previous prime is 2157945161. The next prime is 2157945193. The reversal of 2157945173 is 3715497512.

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 1460615524 + 697329649 = 38218^2 + 26407^2 .

It is a cyclic number.

It is not a de Polignac number, because 2157945173 - 2¹⁴ = 2157928789 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 (2157945193) 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, 65186 + ... + 92547.

It is an arithmetic number, because the mean of its divisors is an integer number (539529147).

Almost surely, 2^2157945173 is an apocalyptic number.

It is an amenable number.

2157945173 is a deficient number, since it is larger than the sum of its proper divisors (171415).

2157945173 is a wasteful number, since it uses less digits than its factorization.

2157945173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171414.

The product of its digits is 264600, while the sum is 44.

The square root of 2157945173 is about 46453.6884757282. The cubic root of 2157945173 is about 1292.2507774335.

The spelling of 2157945173 in words is "two billion, one hundred fifty-seven million, nine hundred forty-five thousand, one hundred seventy-three".