2157015 has 16 divisors (see below), whose sum is σ = 3944448. Its totient is φ = 986016.

The previous prime is 2157007. The next prime is 2157017. The reversal of 2157015 is 5107512.

2157015 = 386² + 387² + ... + 399².

It is not a de Polignac number, because 2157015 - 2³ = 2157007 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

2157015 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2156982 and 2157000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157017) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10167 + ... + 10376.

It is an arithmetic number, because the mean of its divisors is an integer number (246528).

2^2157015 is an apocalyptic number.

2157015 is a deficient number, since it is larger than the sum of its proper divisors (1787433).

2157015 is a wasteful number, since it uses less digits than its factorization.

2157015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20558.

The product of its (nonzero) digits is 350, while the sum is 21.

The square root of 2157015 is about 1468.6779769575. The cubic root of 2157015 is about 129.2065077700.

The spelling of 2157015 in words is "two million, one hundred fifty-seven thousand, fifteen".