133640823 has 4 divisors (see below), whose sum is σ = 178187768. Its totient is φ = 89093880.

The previous prime is 133640821. The next prime is 133640827. The reversal of 133640823 is 328046331.

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

It is not a de Polignac number, because 133640823 - 2¹ = 133640821 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 (133640821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22273468 + ... + 22273473.

It is an arithmetic number, because the mean of its divisors is an integer number (44546942).

Almost surely, 2^133640823 is an apocalyptic number.

133640823 is a deficient number, since it is larger than the sum of its proper divisors (44546945).

133640823 is an equidigital number, since it uses as much as digits as its factorization.

133640823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44546944.

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 133640823 is about 11560.3124092734. The cubic root of 133640823 is about 511.2653738081.

The spelling of 133640823 in words is "one hundred thirty-three million, six hundred forty thousand, eight hundred twenty-three".