639489146 has 4 divisors (see below), whose sum is σ = 959233722. Its totient is φ = 319744572.

The previous prime is 639489143. The next prime is 639489181. The reversal of 639489146 is 641984936.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 440538121 + 198951025 = 20989^2 + 14105^2 .

It is a junction number, because it is equal to n+sod(n) for n = 639489094 and 639489103.

It is not an unprimeable number, because it can be changed into a prime (639489143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159872285 + ... + 159872288.

Almost surely, 2^639489146 is an apocalyptic number.

639489146 is a deficient number, since it is larger than the sum of its proper divisors (319744576).

639489146 is a wasteful number, since it uses less digits than its factorization.

639489146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319744575.

The product of its digits is 1119744, while the sum is 50.

The square root of 639489146 is about 25288.1226270358. The cubic root of 639489146 is about 861.5445229824.

The spelling of 639489146 in words is "six hundred thirty-nine million, four hundred eighty-nine thousand, one hundred forty-six".