133923491 has 4 divisors (see below), whose sum is σ = 144225312. Its totient is φ = 123621672.

The previous prime is 133923481. The next prime is 133923497. The reversal of 133923491 is 194329331.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 194329331 = 7 ⋅27761333.

It is a cyclic number.

It is not a de Polignac number, because 133923491 - 2¹⁸ = 133661347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133923497) 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, 5150891 + ... + 5150916.

It is an arithmetic number, because the mean of its divisors is an integer number (36056328).

Almost surely, 2^133923491 is an apocalyptic number.

133923491 is a deficient number, since it is larger than the sum of its proper divisors (10301821).

133923491 is a wasteful number, since it uses less digits than its factorization.

133923491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10301820.

The product of its digits is 17496, while the sum is 35.

The square root of 133923491 is about 11572.5317454738. The cubic root of 133923491 is about 511.6255845711.

The spelling of 133923491 in words is "one hundred thirty-three million, nine hundred twenty-three thousand, four hundred ninety-one".