647642245 has 8 divisors (see below), whose sum is σ = 791834616. Its totient is φ = 508337856.

The previous prime is 647642243. The next prime is 647642249. The reversal of 647642245 is 542246746.

It can be written as a sum of positive squares in 4 ways, for example, as 205549569 + 442092676 = 14337^2 + 21026^2 .

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 647642245 - 2¹ = 647642243 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 647642198 and 647642207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647642243) 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, 1221702 + ... + 1222231.

It is an arithmetic number, because the mean of its divisors is an integer number (98979327).

Almost surely, 2^647642245 is an apocalyptic number.

It is an amenable number.

647642245 is a deficient number, since it is larger than the sum of its proper divisors (144192371).

647642245 is a wasteful number, since it uses less digits than its factorization.

647642245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2443991.

The product of its digits is 322560, while the sum is 40.

The square root of 647642245 is about 25448.8161807185. The cubic root of 647642245 is about 865.1904622528.

The spelling of 647642245 in words is "six hundred forty-seven million, six hundred forty-two thousand, two hundred forty-five".