2157945 has 16 divisors (see below), whose sum is σ = 3471552. Its totient is φ = 1144640.

The previous prime is 2157923. The next prime is 2157989. The reversal of 2157945 is 5497512.

It is not a de Polignac number, because 2157945 - 2⁵ = 2157913 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4150 + ... + 4640.

It is an arithmetic number, because the mean of its divisors is an integer number (216972).

2^2157945 is an apocalyptic number.

It is an amenable number.

2157945 is a deficient number, since it is larger than the sum of its proper divisors (1313607).

2157945 is a wasteful number, since it uses less digits than its factorization.

2157945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 792.

The product of its digits is 12600, while the sum is 33.

The square root of 2157945 is about 1468.9945541084. The cubic root of 2157945 is about 129.2250742901.

The spelling of 2157945 in words is "two million, one hundred fifty-seven thousand, nine hundred forty-five".