639763893 has 8 divisors (see below), whose sum is σ = 947798400. Its totient is φ = 426509244.

The previous prime is 639763871. The next prime is 639763921. The reversal of 639763893 is 398367936.

It is not a de Polignac number, because 639763893 - 2¹⁰ = 639762869 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639763493) 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, 11847453 + ... + 11847506.

It is an arithmetic number, because the mean of its divisors is an integer number (118474800).

Almost surely, 2^639763893 is an apocalyptic number.

It is an amenable number.

639763893 is a deficient number, since it is larger than the sum of its proper divisors (308034507).

639763893 is a wasteful number, since it uses less digits than its factorization.

639763893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23694968 (or 23694962 counting only the distinct ones).

The product of its digits is 4408992, while the sum is 54.

The square root of 639763893 is about 25293.5543765600. The cubic root of 639763893 is about 861.6678885800.

The spelling of 639763893 in words is "six hundred thirty-nine million, seven hundred sixty-three thousand, eight hundred ninety-three".