3666610581 has 4 divisors (see below), whose sum is σ = 4888814112. Its totient is φ = 2444407052.

The previous prime is 3666610567. The next prime is 3666610589. The reversal of 3666610581 is 1850166663.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 3666610581 - 2¹⁸ = 3666348437 is a prime.

It is a super-2 number, since 2×3666610581² = 26888066305402315122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3666610589) 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, 611101761 + ... + 611101766.

It is an arithmetic number, because the mean of its divisors is an integer number (1222203528).

Almost surely, 2^3666610581 is an apocalyptic number.

It is an amenable number.

3666610581 is a deficient number, since it is larger than the sum of its proper divisors (1222203531).

3666610581 is a wasteful number, since it uses less digits than its factorization.

3666610581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1222203530.

The product of its (nonzero) digits is 155520, while the sum is 42.

The square root of 3666610581 is about 60552.5439680283. The cubic root of 3666610581 is about 1542.0138073863.

The spelling of 3666610581 in words is "three billion, six hundred sixty-six million, six hundred ten thousand, five hundred eighty-one".