136120221661 has 12 divisors (see below), whose sum is σ = 142661822940. Its totient is φ = 129867045440.

The previous prime is 136120221641. The next prime is 136120221673. The reversal of 136120221661 is 166122021631.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 82987205625 + 53133016036 = 288075^2 + 230506^2 .

It is a de Polignac number, because none of the positive numbers 2^k-136120221661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (136120221641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 124960 + ... + 536521.

It is an arithmetic number, because the mean of its divisors is an integer number (11888485245).

Almost surely, 2^136120221661 is an apocalyptic number.

It is an amenable number.

136120221661 is a deficient number, since it is larger than the sum of its proper divisors (6541601279).

136120221661 is an equidigital number, since it uses as much as digits as its factorization.

136120221661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661916 (or 661893 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The spelling of 136120221661 in words is "one hundred thirty-six billion, one hundred twenty million, two hundred twenty-one thousand, six hundred sixty-one".