639493546 has 4 divisors (see below), whose sum is σ = 959240322. Its totient is φ = 319746772.

The previous prime is 639493537. The next prime is 639493553. The reversal of 639493546 is 645394936.

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., 547045321 + 92448225 = 23389^2 + 9615^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 639493546.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159873385 + ... + 159873388.

Almost surely, 2^639493546 is an apocalyptic number.

639493546 is a deficient number, since it is larger than the sum of its proper divisors (319746776).

639493546 is a wasteful number, since it uses less digits than its factorization.

639493546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319746775.

The product of its digits is 2099520, while the sum is 49.

The square root of 639493546 is about 25288.2096242498. The cubic root of 639493546 is about 861.5464989279.

The spelling of 639493546 in words is "six hundred thirty-nine million, four hundred ninety-three thousand, five hundred forty-six".