647720319 has 8 divisors (see below), whose sum is σ = 901176192. Its totient is φ = 413039000.

The previous prime is 647720303. The next prime is 647720321. The reversal of 647720319 is 913027746.

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 647720319 - 2⁴ = 647720303 is a prime.

It is a super-2 number, since 2×647720319² = 839083223290923522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647720369) 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, 4693557 + ... + 4693694.

It is an arithmetic number, because the mean of its divisors is an integer number (112647024).

Almost surely, 2^647720319 is an apocalyptic number.

647720319 is a gapful number since it is divisible by the number (69) formed by its first and last digit.

647720319 is a deficient number, since it is larger than the sum of its proper divisors (253455873).

647720319 is a wasteful number, since it uses less digits than its factorization.

647720319 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9387277.

The product of its (nonzero) digits is 63504, while the sum is 39.

The square root of 647720319 is about 25450.3500761777. The cubic root of 647720319 is about 865.2252274164.

It can be divided in two parts, 6477 and 20319, that added together give a triangular number (26796 = T₂₃₁).

The spelling of 647720319 in words is "six hundred forty-seven million, seven hundred twenty thousand, three hundred nineteen".