133205761 has 32 divisors (see below), whose sum is σ = 158802336. Its totient is φ = 110592000.

The previous prime is 133205759. The next prime is 133205773. The reversal of 133205761 is 167502331.

It can be written as a sum of positive squares in 16 ways, for example, as 80730225 + 52475536 = 8985^2 + 7244^2 .

It is a 3-Lehmer number, since φ(133205761) divides (133205761-1)³.

It is a cyclic number.

It is a Carmichael number.

It is not a de Polignac number, because 133205761 - 2¹ = 133205759 is a prime.

It is a deceptive number, since it divides R_133205760.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133205731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 552601 + ... + 552841.

It is an arithmetic number, because the mean of its divisors is an integer number (4962573).

It is a Poulet number, since it divides 2^133205760-1.

Almost surely, 2^133205761 is an apocalyptic number.

It is an amenable number.

133205761 is a deficient number, since it is larger than the sum of its proper divisors (25596575).

133205761 is a wasteful number, since it uses less digits than its factorization.

133205761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373.

The product of its (nonzero) digits is 3780, while the sum is 28.

The square root of 133205761 is about 11541.4800177447. The cubic root of 133205761 is about 510.7099697998.

The spelling of 133205761 in words is "one hundred thirty-three million, two hundred five thousand, seven hundred sixty-one".