133681815791 has 16 divisors (see below), whose sum is σ = 147918887424. Its totient is φ = 120277417344.

The previous prime is 133681815781. The next prime is 133681815833. The reversal of 133681815791 is 197518186331.

It is a cyclic number.

It is not a de Polignac number, because 133681815791 - 2³⁴ = 116501946607 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 (133681815781) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1911125 + ... + 1979838.

It is an arithmetic number, because the mean of its divisors is an integer number (9244930464).

Almost surely, 2^133681815791 is an apocalyptic number.

133681815791 is a deficient number, since it is larger than the sum of its proper divisors (14237071633).

133681815791 is a wasteful number, since it uses less digits than its factorization.

133681815791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3891070.

The product of its digits is 1088640, while the sum is 53.

The spelling of 133681815791 in words is "one hundred thirty-three billion, six hundred eighty-one million, eight hundred fifteen thousand, seven hundred ninety-one".