642137 has 4 divisors (see below), whose sum is σ = 670080. Its totient is φ = 614196.

The previous prime is 642133. The next prime is 642149. The reversal of 642137 is 731246.

642137 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 642137 - 2² = 642133 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 27919 = 642137 / (6 + 4 + 2 + 1 + 3 + 7).

It is a Duffinian number.

It is a zygodrome in base 9.

It is not an unprimeable number, because it can be changed into a prime (642133) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13937 + ... + 13982.

It is an arithmetic number, because the mean of its divisors is an integer number (167520).

2⁶⁴²¹³⁷ is an apocalyptic number.

It is an amenable number.

642137 is a deficient number, since it is larger than the sum of its proper divisors (27943).

642137 is a wasteful number, since it uses less digits than its factorization.

642137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27942.

The product of its digits is 1008, while the sum is 23.

The square root of 642137 is about 801.3345119237. The cubic root of 642137 is about 86.2731982688.

The spelling of 642137 in words is "six hundred forty-two thousand, one hundred thirty-seven".