647720431 has 8 divisors (see below), whose sum is σ = 682087280. Its totient is φ = 613381248.

The previous prime is 647720429. The next prime is 647720453. The reversal of 647720431 is 134027746.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 647720431 - 2¹ = 647720429 is a prime.

It is a super-2 number, since 2×647720431² = 839083513469651522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647720471) 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, 55825 + ... + 66421.

It is an arithmetic number, because the mean of its divisors is an integer number (85260910).

Almost surely, 2^647720431 is an apocalyptic number.

647720431 is a deficient number, since it is larger than the sum of its proper divisors (34366849).

647720431 is a wasteful number, since it uses less digits than its factorization.

647720431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13833.

The product of its (nonzero) digits is 28224, while the sum is 34.

The square root of 647720431 is about 25450.3522765403. The cubic root of 647720431 is about 865.2252772863.

The spelling of 647720431 in words is "six hundred forty-seven million, seven hundred twenty thousand, four hundred thirty-one".