133621191 has 64 divisors (see below), whose sum is σ = 232980480. Its totient is φ = 74844000.

The previous prime is 133621151. The next prime is 133621193. The reversal of 133621191 is 191126331.

133621191 is a `hidden beast` number, since 1 + 33 + 621 + 1 + 9 + 1 = 666.

It is not a de Polignac number, because 133621191 - 2¹⁵ = 133588423 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133621193) 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 63 ways as a sum of consecutive naturals, for example, 211446 + ... + 212076.

It is an arithmetic number, because the mean of its divisors is an integer number (3640320).

Almost surely, 2^133621191 is an apocalyptic number.

133621191 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

133621191 is a deficient number, since it is larger than the sum of its proper divisors (99359289).

133621191 is a wasteful number, since it uses less digits than its factorization.

133621191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 705 (or 699 counting only the distinct ones).

The product of its digits is 972, while the sum is 27.

The square root of 133621191 is about 11559.4632660864. The cubic root of 133621191 is about 511.2403374130.

The spelling of 133621191 in words is "one hundred thirty-three million, six hundred twenty-one thousand, one hundred ninety-one".