642999 has 16 divisors (see below), whose sum is σ = 996608. Its totient is φ = 361152.

The previous prime is 642997. The next prime is 643009. The reversal of 642999 is 999246.

It is not a de Polignac number, because 642999 - 2¹ = 642997 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

642999 is a modest number, since divided by 999 gives 642 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642997) 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, 1179 + ... + 1635.

It is an arithmetic number, because the mean of its divisors is an integer number (62288).

2⁶⁴²⁹⁹⁹ is an apocalyptic number.

642999 is a deficient number, since it is larger than the sum of its proper divisors (353609).

642999 is a wasteful number, since it uses less digits than its factorization.

642999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 534.

The product of its digits is 34992, while the sum is 39.

The square root of 642999 is about 801.8721843286. The cubic root of 642999 is about 86.3117851772.

The spelling of 642999 in words is "six hundred forty-two thousand, nine hundred ninety-nine".