647388387 has 48 divisors (see below), whose sum is σ = 1015872000. Its totient is φ = 395969472.

The previous prime is 647388353. The next prime is 647388433. The reversal of 647388387 is 783883746.

It is not a de Polignac number, because 647388387 - 2¹¹ = 647386339 is a prime.

It is a super-2 number, since 2×647388387² = 838223447244923538, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (647388787) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 875664 + ... + 876402.

It is an arithmetic number, because the mean of its divisors is an integer number (21164000).

Almost surely, 2^647388387 is an apocalyptic number.

647388387 is a deficient number, since it is larger than the sum of its proper divisors (368483613).

647388387 is a wasteful number, since it uses less digits than its factorization.

647388387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 920 (or 917 counting only the distinct ones).

The product of its digits is 5419008, while the sum is 54.

The square root of 647388387 is about 25443.8280728353. The cubic root of 647388387 is about 865.0774038344.

The spelling of 647388387 in words is "six hundred forty-seven million, three hundred eighty-eight thousand, three hundred eighty-seven".