133161281 has 16 divisors (see below), whose sum is σ = 150139008. Its totient is φ = 117062400.

The previous prime is 133161269. The next prime is 133161319. The reversal of 133161281 is 182161331.

It is a cyclic number.

It is not a de Polignac number, because 133161281 - 2¹⁴ = 133144897 is a prime.

It is a super-2 number, since 2×133161281² = 35463853515121922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 133161281.

It is not an unprimeable number, because it can be changed into a prime (133161211) 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, 39785 + ... + 43001.

It is an arithmetic number, because the mean of its divisors is an integer number (9383688).

Almost surely, 2^133161281 is an apocalyptic number.

133161281 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

133161281 is a deficient number, since it is larger than the sum of its proper divisors (16977727).

133161281 is a wasteful number, since it uses less digits than its factorization.

133161281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3352.

The product of its digits is 864, while the sum is 26.

The square root of 133161281 is about 11539.5528942849. The cubic root of 133161281 is about 510.6531181335.

Subtracting 133161281 from its reverse (182161331), we obtain a triangular number (49000050 = T₉₈₉₉).

The spelling of 133161281 in words is "one hundred thirty-three million, one hundred sixty-one thousand, two hundred eighty-one".