36661581065 has 4 divisors (see below), whose sum is σ = 43993897284. Its totient is φ = 29329264848.

The previous prime is 36661581029. The next prime is 36661581071. The reversal of 36661581065 is 56018516663.

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

It can be written as a sum of positive squares in 2 ways, for example, as 14397360121 + 22264220944 = 119989^2 + 149212^2 .

It is a cyclic number.

It is not a de Polignac number, because 36661581065 - 2²² = 36657386761 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3666158102 + ... + 3666158111.

It is an arithmetic number, because the mean of its divisors is an integer number (10998474321).

Almost surely, 2^36661581065 is an apocalyptic number.

It is an amenable number.

36661581065 is a deficient number, since it is larger than the sum of its proper divisors (7332316219).

36661581065 is an equidigital number, since it uses as much as digits as its factorization.

36661581065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7332316218.

The product of its (nonzero) digits is 777600, while the sum is 47.

The spelling of 36661581065 in words is "thirty-six billion, six hundred sixty-one million, five hundred eighty-one thousand, sixty-five".