642154 has 4 divisors (see below), whose sum is σ = 963234. Its totient is φ = 321076.

The previous prime is 642151. The next prime is 642157. The reversal of 642154 is 451246.

642154 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.

It is an interprime number because it is at equal distance from previous prime (642151) and next prime (642157).

It can be written as a sum of positive squares in only one way, i.e., 452929 + 189225 = 673^2 + 435^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (642151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160537 + ... + 160540.

2⁶⁴²¹⁵⁴ is an apocalyptic number.

642154 is a deficient number, since it is larger than the sum of its proper divisors (321080).

642154 is a wasteful number, since it uses less digits than its factorization.

642154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321079.

The product of its digits is 960, while the sum is 22.

The square root of 642154 is about 801.3451191590. The cubic root of 642154 is about 86.2739595972.

The spelling of 642154 in words is "six hundred forty-two thousand, one hundred fifty-four".