642387 has 4 divisors (see below), whose sum is σ = 856520. Its totient is φ = 428256.

The previous prime is 642373. The next prime is 642403. The reversal of 642387 is 783246.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 642387 - 2¹⁵ = 609619 is a prime.

It is a super-2 number, since 2×642387² = 825322115538, which contains 22 as substring.

It is an Ulam number.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642487) 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 3 ways as a sum of consecutive naturals, for example, 107062 + ... + 107067.

It is an arithmetic number, because the mean of its divisors is an integer number (214130).

2⁶⁴²³⁸⁷ is an apocalyptic number.

642387 is a deficient number, since it is larger than the sum of its proper divisors (214133).

642387 is a wasteful number, since it uses less digits than its factorization.

642387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214132.

The product of its digits is 8064, while the sum is 30.

The square root of 642387 is about 801.4904865312. The cubic root of 642387 is about 86.2843929210.

The spelling of 642387 in words is "six hundred forty-two thousand, three hundred eighty-seven".