638348944 has 10 divisors (see below), whose sum is σ = 1236801110. Its totient is φ = 319174464.

The previous prime is 638348941. The next prime is 638348981. The reversal of 638348944 is 449843836.

It can be written as a sum of positive squares in only one way, i.e., 479084544 + 159264400 = 21888^2 + 12620^2 .

It is not an unprimeable number, because it can be changed into a prime (638348941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19948389 + ... + 19948420.

It is an arithmetic number, because the mean of its divisors is an integer number (123680111).

Almost surely, 2^638348944 is an apocalyptic number.

It is an amenable number.

638348944 is a deficient number, since it is larger than the sum of its proper divisors (598452166).

638348944 is a wasteful number, since it uses less digits than its factorization.

638348944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39896817 (or 39896811 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 49.

The square root of 638348944 is about 25265.5683490398. The cubic root of 638348944 is about 861.0321769407.

The spelling of 638348944 in words is "six hundred thirty-eight million, three hundred forty-eight thousand, nine hundred forty-four".