1647385745 has 16 divisors (see below), whose sum is σ = 2051159760. Its totient is φ = 1268649984.

The previous prime is 1647385739. The next prime is 1647385763. The reversal of 1647385745 is 5475837461.

It is a Cunningham number, because it is equal to 40588²+1.

It can be written as a sum of positive squares in 8 ways, for example, as 228130816 + 1419254929 = 15104^2 + 37673^2 .

It is a cyclic number.

It is not a de Polignac number, because 1647385745 - 2¹² = 1647381649 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1647385693 and 1647385702.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32009 + ... + 65721.

It is an arithmetic number, because the mean of its divisors is an integer number (128197485).

Almost surely, 2^1647385745 is an apocalyptic number.

It is an amenable number.

1647385745 is a deficient number, since it is larger than the sum of its proper divisors (403774015).

1647385745 is a wasteful number, since it uses less digits than its factorization.

1647385745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34084.

The product of its digits is 2822400, while the sum is 50.

The square root of 1647385745 is about 40588.0000123189. Note that the first 4 decimals coincide. The cubic root of 1647385745 is about 1181.0413447044.

The spelling of 1647385745 in words is "one billion, six hundred forty-seven million, three hundred eighty-five thousand, seven hundred forty-five".