642015 has 24 divisors (see below), whose sum is σ = 1214928. Its totient is φ = 311040.

The previous prime is 642013. The next prime is 642049. The reversal of 642015 is 510246.

It is a happy number.

It is not a de Polignac number, because 642015 - 2¹ = 642013 is a prime.

642015 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642011) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 154 + ... + 1143.

It is an arithmetic number, because the mean of its divisors is an integer number (50622).

2⁶⁴²⁰¹⁵ is an apocalyptic number.

642015 is a deficient number, since it is larger than the sum of its proper divisors (572913).

642015 is a wasteful number, since it uses less digits than its factorization.

642015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1319 (or 1316 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 642015 is about 801.2583852915. The cubic root of 642015 is about 86.2677342235.

Subtracting from 642015 its reverse (510246), we obtain a square (131769 = 363²).

The spelling of 642015 in words is "six hundred forty-two thousand, fifteen".