647291940 has 24 divisors (see below), whose sum is σ = 1812417600. Its totient is φ = 172611168.

The previous prime is 647291929. The next prime is 647291947. The reversal of 647291940 is 49192746.

It is a junction number, because it is equal to n+sod(n) for n = 647291892 and 647291901.

It is not an unprimeable number, because it can be changed into a prime (647291947) 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, 5394040 + ... + 5394159.

It is an arithmetic number, because the mean of its divisors is an integer number (75517400).

Almost surely, 2^647291940 is an apocalyptic number.

647291940 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

647291940 is an abundant number, since it is smaller than the sum of its proper divisors (1165125660).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

647291940 is a wasteful number, since it uses less digits than its factorization.

647291940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10788211 (or 10788209 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 42.

The square root of 647291940 is about 25441.9327096036. The cubic root of 647291940 is about 865.0344423676.

The spelling of 647291940 in words is "six hundred forty-seven million, two hundred ninety-one thousand, nine hundred forty".