642388 has 12 divisors (see below), whose sum is σ = 1151892. Its totient is φ = 313280.

The previous prime is 642373. The next prime is 642403. The reversal of 642388 is 883246.

It is a happy number.

642388 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (642373) and next prime (642403).

It can be written as a sum of positive squares in 2 ways, for example, as 248004 + 394384 = 498^2 + 628^2 .

It is a congruent number.

It is an unprimeable number.

642388 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1795 + ... + 2122.

It is an arithmetic number, because the mean of its divisors is an integer number (95991).

2⁶⁴²³⁸⁸ is an apocalyptic number.

It is an amenable number.

642388 is a deficient number, since it is larger than the sum of its proper divisors (509504).

642388 is a wasteful number, since it uses less digits than its factorization.

642388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3962 (or 3960 counting only the distinct ones).

The product of its digits is 9216, while the sum is 31.

The square root of 642388 is about 801.4911103687. The cubic root of 642388 is about 86.2844376937.

It can be divided in two parts, 64238 and 8, that added together give a palindrome (64246).

The spelling of 642388 in words is "six hundred forty-two thousand, three hundred eighty-eight".