3653427781 has 4 divisors (see below), whose sum is σ = 3654980172. Its totient is φ = 3651875392.

The previous prime is 3653427773. The next prime is 3653427793. The reversal of 3653427781 is 1877243563.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1877243563 = 13 ⋅144403351.

It can be written as a sum of positive squares in 2 ways, for example, as 1475712225 + 2177715556 = 38415^2 + 46666^2 .

It is a cyclic number.

It is not a de Polignac number, because 3653427781 - 2³ = 3653427773 is a prime.

It is a super-2 number, since 2×3653427781² = 26695069101965167922, 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 (3653427751) 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, 772660 + ... + 777373.

It is an arithmetic number, because the mean of its divisors is an integer number (913745043).

Almost surely, 2^3653427781 is an apocalyptic number.

It is an amenable number.

3653427781 is a deficient number, since it is larger than the sum of its proper divisors (1552391).

3653427781 is a wasteful number, since it uses less digits than its factorization.

3653427781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1552390.

The product of its digits is 846720, while the sum is 46.

The square root of 3653427781 is about 60443.5917281559. The cubic root of 3653427781 is about 1540.1635544794.

The spelling of 3653427781 in words is "three billion, six hundred fifty-three million, four hundred twenty-seven thousand, seven hundred eighty-one".