133555531 has 2 divisors, whose sum is σ = 133555532. Its totient is φ = 133555530.

The previous prime is 133555511. The next prime is 133555561. The reversal of 133555531 is 135555331.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-133555531 is a prime.

It is a super-2 number, since 2×133555531² = 35674159721383922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 133555493 and 133555502.

It is not a weakly prime, because it can be changed into another prime (133555501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66777765 + 66777766.

It is an arithmetic number, because the mean of its divisors is an integer number (66777766).

Almost surely, 2^133555531 is an apocalyptic number.

133555531 is a deficient number, since it is larger than the sum of its proper divisors (1).

133555531 is an equidigital number, since it uses as much as digits as its factorization.

133555531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16875, while the sum is 31.

The square root of 133555531 is about 11556.6228198380. The cubic root of 133555531 is about 511.1565843792.

The spelling of 133555531 in words is "one hundred thirty-three million, five hundred fifty-five thousand, five hundred thirty-one".