639154 has 4 divisors (see below), whose sum is σ = 958734. Its totient is φ = 319576.

The previous prime is 639151. The next prime is 639157. The reversal of 639154 is 451936.

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 (639151) and next prime (639157).

It can be written as a sum of positive squares in only one way, i.e., 497025 + 142129 = 705^2 + 377^2 .

It is not an unprimeable number, because it can be changed into a prime (639151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159787 + ... + 159790.

2⁶³⁹¹⁵⁴ is an apocalyptic number.

639154 is a deficient number, since it is larger than the sum of its proper divisors (319580).

639154 is a wasteful number, since it uses less digits than its factorization.

639154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319579.

The product of its digits is 3240, while the sum is 28.

The square root of 639154 is about 799.4710751491. The cubic root of 639154 is about 86.1393989462.

The spelling of 639154 in words is "six hundred thirty-nine thousand, one hundred fifty-four".