3661128391 has 4 divisors (see below), whose sum is σ = 3667160512. Its totient is φ = 3655096272.

The previous prime is 3661128389. The next prime is 3661128397. The reversal of 3661128391 is 1938211663.

3661128391 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 3661128391 - 2¹ = 3661128389 is a prime.

It is a super-2 number, since 2×3661128391² = 26807722190772497762, 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 (3661128397) 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, 3015150 + ... + 3016363.

It is an arithmetic number, because the mean of its divisors is an integer number (916790128).

Almost surely, 2^3661128391 is an apocalyptic number.

3661128391 is a deficient number, since it is larger than the sum of its proper divisors (6032121).

3661128391 is an equidigital number, since it uses as much as digits as its factorization.

3661128391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6032120.

The product of its digits is 46656, while the sum is 40.

The square root of 3661128391 is about 60507.2589942727. The cubic root of 3661128391 is about 1541.2449020467.

The spelling of 3661128391 in words is "three billion, six hundred sixty-one million, one hundred twenty-eight thousand, three hundred ninety-one".