2151687 has 4 divisors (see below), whose sum is σ = 2868920. Its totient is φ = 1434456.

The previous prime is 2151683. The next prime is 2151701. The reversal of 2151687 is 7861512.

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

It is not a de Polignac number, because 2151687 - 2² = 2151683 is a prime.

It is an Ulam number.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2151683) 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, 358612 + ... + 358617.

It is an arithmetic number, because the mean of its divisors is an integer number (717230).

2^2151687 is an apocalyptic number.

2151687 is a deficient number, since it is larger than the sum of its proper divisors (717233).

2151687 is an equidigital number, since it uses as much as digits as its factorization.

2151687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 717232.

The product of its digits is 3360, while the sum is 30.

The square root of 2151687 is about 1466.8629792861. The cubic root of 2151687 is about 129.1000365797.

The spelling of 2151687 in words is "two million, one hundred fifty-one thousand, six hundred eighty-seven".