639484451 has 4 divisors (see below), whose sum is σ = 639795600. Its totient is φ = 639173304.

The previous prime is 639484409. The next prime is 639484457. The reversal of 639484451 is 154484936.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-639484451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639484457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 152471 + ... + 156608.

It is an arithmetic number, because the mean of its divisors is an integer number (159948900).

Almost surely, 2^639484451 is an apocalyptic number.

639484451 is a deficient number, since it is larger than the sum of its proper divisors (311149).

639484451 is a wasteful number, since it uses less digits than its factorization.

639484451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311148.

The product of its digits is 414720, while the sum is 44.

The square root of 639484451 is about 25288.0297967240. The cubic root of 639484451 is about 861.5424145486.

The spelling of 639484451 in words is "six hundred thirty-nine million, four hundred eighty-four thousand, four hundred fifty-one".