642870 has 32 divisors (see below), whose sum is σ = 1715040. Its totient is φ = 171360.

The previous prime is 642869. The next prime is 642871. The reversal of 642870 is 78246.

642870 is nontrivially palindromic in base 4.

It is an interprime number because it is at equal distance from previous prime (642869) and next prime (642871).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a nialpdrome in base 15.

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 642870.

It is not an unprimeable number, because it can be changed into a prime (642871) 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, 921 + ... + 1460.

It is an arithmetic number, because the mean of its divisors is an integer number (53595).

2⁶⁴²⁸⁷⁰ is an apocalyptic number.

642870 is an abundant number, since it is smaller than the sum of its proper divisors (1072170).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

642870 is a wasteful number, since it uses less digits than its factorization.

642870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2397 (or 2391 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 642870 is about 801.7917435344. The cubic root of 642870 is about 86.3060127655.

The spelling of 642870 in words is "six hundred forty-two thousand, eight hundred seventy".