133263991 has 8 divisors (see below), whose sum is σ = 153092384. Its totient is φ = 113633280.

The previous prime is 133263971. The next prime is 133264007. The reversal of 133263991 is 199362331.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 133263991 - 2⁵ = 133263959 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 133263991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133263971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47970 + ... + 50671.

It is an arithmetic number, because the mean of its divisors is an integer number (19136548).

Almost surely, 2^133263991 is an apocalyptic number.

133263991 is a deficient number, since it is larger than the sum of its proper divisors (19828393).

133263991 is an equidigital number, since it uses as much as digits as its factorization.

133263991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98841.

The product of its digits is 26244, while the sum is 37.

The square root of 133263991 is about 11544.0023821896. The cubic root of 133263991 is about 510.7843767649.

The spelling of 133263991 in words is "one hundred thirty-three million, two hundred sixty-three thousand, nine hundred ninety-one".