133538431 has 4 divisors (see below), whose sum is σ = 143810632. Its totient is φ = 123266232.

The previous prime is 133538401. The next prime is 133538453. The reversal of 133538431 is 134835331.

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 133538431 - 2¹⁵ = 133505663 is a prime.

It is a super-2 number, since 2×133538431² = 35665025107883522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 133538393 and 133538402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133538401) 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, 5136081 + ... + 5136106.

It is an arithmetic number, because the mean of its divisors is an integer number (35952658).

Almost surely, 2^133538431 is an apocalyptic number.

133538431 is a deficient number, since it is larger than the sum of its proper divisors (10272201).

133538431 is a wasteful number, since it uses less digits than its factorization.

133538431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10272200.

The product of its digits is 12960, while the sum is 31.

The square root of 133538431 is about 11555.8829606396. The cubic root of 133538431 is about 511.1347678594.

The spelling of 133538431 in words is "one hundred thirty-three million, five hundred thirty-eight thousand, four hundred thirty-one".