1645663657364 has 12 divisors (see below), whose sum is σ = 2883656414100. Its totient is φ = 821761824768.

The previous prime is 1645663657349. The next prime is 1645663657369. The reversal of 1645663657364 is 4637563665461.

It can be written as a sum of positive squares in 2 ways, for example, as 748816776964 + 896846880400 = 865342^2 + 947020^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1645663657297 and 1645663657306.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645663657369) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 267497519 + ... + 267503670.

It is an arithmetic number, because the mean of its divisors is an integer number (240304701175).

Almost surely, 2^{1645663657364} is an apocalyptic number.

It is an amenable number.

1645663657364 is a deficient number, since it is larger than the sum of its proper divisors (1237992756736).

1645663657364 is a wasteful number, since it uses less digits than its factorization.

1645663657364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 535001962 (or 535001960 counting only the distinct ones).

The product of its digits is 195955200, while the sum is 62.

The spelling of 1645663657364 in words is "one trillion, six hundred forty-five billion, six hundred sixty-three million, six hundred fifty-seven thousand, three hundred sixty-four".