3645864781 has 8 divisors (see below), whose sum is σ = 3931109784. Its totient is φ = 3361304640.

The previous prime is 3645864743. The next prime is 3645864791. The reversal of 3645864781 is 1874685463.

It can be written as a sum of positive squares in 4 ways, for example, as 20620681 + 3625244100 = 4541^2 + 60210^2 .

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 3645864781 - 2⁹ = 3645864269 is a prime.

It is a super-2 number, since 2×3645864781² = 26584660002672355922, 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 (3645864791) 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, 160126 + ... + 181471.

It is an arithmetic number, because the mean of its divisors is an integer number (491388723).

Almost surely, 2^3645864781 is an apocalyptic number.

It is an amenable number.

3645864781 is a deficient number, since it is larger than the sum of its proper divisors (285245003).

3645864781 is a wasteful number, since it uses less digits than its factorization.

3645864781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342431.

The product of its digits is 3870720, while the sum is 52.

The square root of 3645864781 is about 60380.9968533147. The cubic root of 3645864781 is about 1539.1000505917.

The spelling of 3645864781 in words is "three billion, six hundred forty-five million, eight hundred sixty-four thousand, seven hundred eighty-one".