133509731 has 2 divisors, whose sum is σ = 133509732. Its totient is φ = 133509730.

The previous prime is 133509709. The next prime is 133509737. The reversal of 133509731 is 137905331.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 133509731 - 2⁶ = 133509667 is a prime.

It is a super-2 number, since 2×133509731² = 35649696543384722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (133509737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66754865 + 66754866.

It is an arithmetic number, because the mean of its divisors is an integer number (66754866).

Almost surely, 2^133509731 is an apocalyptic number.

133509731 is a deficient number, since it is larger than the sum of its proper divisors (1).

133509731 is an equidigital number, since it uses as much as digits as its factorization.

133509731 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8505, while the sum is 32.

The square root of 133509731 is about 11554.6411021719. The cubic root of 133509731 is about 511.0981476426.

The spelling of 133509731 in words is "one hundred thirty-three million, five hundred nine thousand, seven hundred thirty-one".