639550851 has 16 divisors (see below), whose sum is σ = 863723520. Its totient is φ = 420901920.

The previous prime is 639550823. The next prime is 639550853. The reversal of 639550851 is 158055936.

It is not a de Polignac number, because 639550851 - 2⁹ = 639550339 is a prime.

It is not an unprimeable number, because it can be changed into a prime (639550853) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 89086 + ... + 95996.

It is an arithmetic number, because the mean of its divisors is an integer number (53982720).

Almost surely, 2^639550851 is an apocalyptic number.

639550851 is a deficient number, since it is larger than the sum of its proper divisors (224172669).

639550851 is a wasteful number, since it uses less digits than its factorization.

639550851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7306.

The product of its (nonzero) digits is 162000, while the sum is 42.

The square root of 639550851 is about 25289.3426367709. The cubic root of 639550851 is about 861.5722325457.

The spelling of 639550851 in words is "six hundred thirty-nine million, five hundred fifty thousand, eight hundred fifty-one".