647987172 has 144 divisors (see below), whose sum is σ = 1912135680. Its totient is φ = 169646400.

The previous prime is 647987161. The next prime is 647987227. The reversal of 647987172 is 271789746.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 345397 + ... + 347267.

It is an arithmetic number, because the mean of its divisors is an integer number (13278720).

Almost surely, 2^647987172 is an apocalyptic number.

647987172 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 647987172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (956067840).

647987172 is an abundant number, since it is smaller than the sum of its proper divisors (1264148508).

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

647987172 is a wasteful number, since it uses less digits than its factorization.

647987172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1942 (or 1933 counting only the distinct ones).

The product of its digits is 1185408, while the sum is 51.

The square root of 647987172 is about 25455.5921557523. The cubic root of 647987172 is about 865.3440319068.

The spelling of 647987172 in words is "six hundred forty-seven million, nine hundred eighty-seven thousand, one hundred seventy-two".