133801991 has 2 divisors, whose sum is σ = 133801992. Its totient is φ = 133801990.

The previous prime is 133801979. The next prime is 133802041. The reversal of 133801991 is 199108331.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-133801991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133801091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66900995 + 66900996.

It is an arithmetic number, because the mean of its divisors is an integer number (66900996).

Almost surely, 2^133801991 is an apocalyptic number.

133801991 is a deficient number, since it is larger than the sum of its proper divisors (1).

133801991 is an equidigital number, since it uses as much as digits as its factorization.

133801991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 35.

The square root of 133801991 is about 11567.2810547682. The cubic root of 133801991 is about 511.4708163120.

The spelling of 133801991 in words is "one hundred thirty-three million, eight hundred one thousand, nine hundred ninety-one".