133661251 has 4 divisors (see below), whose sum is σ = 134216104. Its totient is φ = 133106400.

The previous prime is 133661249. The next prime is 133661273. The reversal of 133661251 is 152166331.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 133661251 - 2¹ = 133661249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133661201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 277065 + ... + 277546.

It is an arithmetic number, because the mean of its divisors is an integer number (33554026).

Almost surely, 2^133661251 is an apocalyptic number.

133661251 is a deficient number, since it is larger than the sum of its proper divisors (554853).

133661251 is an equidigital number, since it uses as much as digits as its factorization.

133661251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 554852.

The product of its digits is 3240, while the sum is 28.

The square root of 133661251 is about 11561.1959156482. The cubic root of 133661251 is about 511.2914227272.

The spelling of 133661251 in words is "one hundred thirty-three million, six hundred sixty-one thousand, two hundred fifty-one".