639811067 has 8 divisors (see below), whose sum is σ = 750975456. Its totient is φ = 533587392.

The previous prime is 639811057. The next prime is 639811087. The reversal of 639811067 is 760118936.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 639811067 - 2⁸ = 639810811 is a prime.

It is not an unprimeable number, because it can be changed into a prime (639811037) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1234898 + ... + 1235415.

It is an arithmetic number, because the mean of its divisors is an integer number (93871932).

Almost surely, 2^639811067 is an apocalyptic number.

639811067 is a deficient number, since it is larger than the sum of its proper divisors (111164389).

639811067 is a wasteful number, since it uses less digits than its factorization.

639811067 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2470357.

The product of its (nonzero) digits is 54432, while the sum is 41.

The square root of 639811067 is about 25294.4868894390. The cubic root of 639811067 is about 861.6890668732.

The spelling of 639811067 in words is "six hundred thirty-nine million, eight hundred eleven thousand, sixty-seven".