642398 has 4 divisors (see below), whose sum is σ = 963600. Its totient is φ = 321198.

The previous prime is 642373. The next prime is 642403. The reversal of 642398 is 893246.

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

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 642398.

It is an unprimeable number.

642398 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 as a sum of consecutive naturals, namely, 160598 + ... + 160601.

It is an arithmetic number, because the mean of its divisors is an integer number (240900).

2⁶⁴²³⁹⁸ is an apocalyptic number.

642398 is a deficient number, since it is larger than the sum of its proper divisors (321202).

642398 is a wasteful number, since it uses less digits than its factorization.

642398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321201.

The product of its digits is 10368, while the sum is 32.

The square root of 642398 is about 801.4973487168. The cubic root of 642398 is about 86.2848854190.

The spelling of 642398 in words is "six hundred forty-two thousand, three hundred ninety-eight".