2157139 has 4 divisors (see below), whose sum is σ = 2170224. Its totient is φ = 2144056.

The previous prime is 2157131. The next prime is 2157149. The reversal of 2157139 is 9317512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2157139 - 2³ = 2157131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2157131) 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, 6292 + ... + 6625.

It is an arithmetic number, because the mean of its divisors is an integer number (542556).

2^2157139 is an apocalyptic number.

2157139 is a deficient number, since it is larger than the sum of its proper divisors (13085).

2157139 is a wasteful number, since it uses less digits than its factorization.

2157139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13084.

The product of its digits is 1890, while the sum is 28.

The square root of 2157139 is about 1468.7201911869. The cubic root of 2157139 is about 129.2089836143.

The spelling of 2157139 in words is "two million, one hundred fifty-seven thousand, one hundred thirty-nine".