642381 has 8 divisors (see below), whose sum is σ = 861120. Its totient is φ = 425952.

The previous prime is 642373. The next prime is 642403. The reversal of 642381 is 183246.

It is a happy number.

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

It is not a de Polignac number, because 642381 - 2³ = 642373 is a prime.

It is a super-2 number, since 2×642381² = 825306698322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 642381.

It is not an unprimeable number, because it can be changed into a prime (642361) 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, 240 + ... + 1158.

It is an arithmetic number, because the mean of its divisors is an integer number (107640).

2⁶⁴²³⁸¹ is an apocalyptic number.

It is an amenable number.

642381 is a deficient number, since it is larger than the sum of its proper divisors (218739).

642381 is a wasteful number, since it uses less digits than its factorization.

642381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1155.

The product of its digits is 1152, while the sum is 24.

The square root of 642381 is about 801.4867434961. The cubic root of 642381 is about 86.2841242833.

The spelling of 642381 in words is "six hundred forty-two thousand, three hundred eighty-one".