2157987 has 8 divisors (see below), whose sum is σ = 3098704. Its totient is φ = 1327968.

The previous prime is 2157923. The next prime is 2157989. The reversal of 2157987 is 7897512.

2157987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2157987 - 2⁶ = 2157923 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 55333 = 2157987 / (2 + 1 + 5 + 7 + 9 + 8 + 7).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2157989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27628 + ... + 27705.

It is an arithmetic number, because the mean of its divisors is an integer number (387338).

2^2157987 is an apocalyptic number.

2157987 is a deficient number, since it is larger than the sum of its proper divisors (940717).

2157987 is a wasteful number, since it uses less digits than its factorization.

2157987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55349.

The product of its digits is 35280, while the sum is 39.

The square root of 2157987 is about 1469.0088495309. The cubic root of 2157987 is about 129.2259126522.

The spelling of 2157987 in words is "two million, one hundred fifty-seven thousand, nine hundred eighty-seven".