133172861 has 4 divisors (see below), whose sum is σ = 133804224. Its totient is φ = 132541500.

The previous prime is 133172833. The next prime is 133172863. The reversal of 133172861 is 168271331.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 168271331 = 463 ⋅363437.

It is a cyclic number.

It is not a de Polignac number, because 133172861 - 2¹⁰ = 133171837 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 (133172863) 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, 315365 + ... + 315786.

It is an arithmetic number, because the mean of its divisors is an integer number (33451056).

Almost surely, 2^133172861 is an apocalyptic number.

It is an amenable number.

133172861 is a deficient number, since it is larger than the sum of its proper divisors (631363).

133172861 is an equidigital number, since it uses as much as digits as its factorization.

133172861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 631362.

The product of its digits is 6048, while the sum is 32.

The square root of 133172861 is about 11540.0546359192. The cubic root of 133172861 is about 510.6679202132.

The spelling of 133172861 in words is "one hundred thirty-three million, one hundred seventy-two thousand, eight hundred sixty-one".