642291 has 16 divisors (see below), whose sum is σ = 946176. Its totient is φ = 385056.

The previous prime is 642281. The next prime is 642359. The reversal of 642291 is 192246.

It is not a de Polignac number, because 642291 - 2⁷ = 642163 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 642291.

It is not an unprimeable number, because it can be changed into a prime (642211) 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, 1486 + ... + 1868.

It is an arithmetic number, because the mean of its divisors is an integer number (59136).

2⁶⁴²²⁹¹ is an apocalyptic number.

642291 is a deficient number, since it is larger than the sum of its proper divisors (303885).

642291 is a wasteful number, since it uses less digits than its factorization.

642291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442.

The product of its digits is 864, while the sum is 24.

The square root of 642291 is about 801.4305958722. The cubic root of 642291 is about 86.2800945181.

The spelling of 642291 in words is "six hundred forty-two thousand, two hundred ninety-one".