133856261 has 16 divisors (see below), whose sum is σ = 168117120. Its totient is φ = 103534080.

The previous prime is 133856243. The next prime is 133856263. The reversal of 133856261 is 162658331.

It is a cyclic number.

It is not a de Polignac number, because 133856261 - 2²² = 129661957 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 (133856263) 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, 4205 + ... + 16893.

It is an arithmetic number, because the mean of its divisors is an integer number (10507320).

Almost surely, 2^133856261 is an apocalyptic number.

133856261 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

133856261 is a deficient number, since it is larger than the sum of its proper divisors (34260859).

133856261 is a wasteful number, since it uses less digits than its factorization.

133856261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12844.

The product of its digits is 25920, while the sum is 35.

The square root of 133856261 is about 11569.6266577621. The cubic root of 133856261 is about 511.5399577077.

The spelling of 133856261 in words is "one hundred thirty-three million, eight hundred fifty-six thousand, two hundred sixty-one".