133778655 has 16 divisors (see below), whose sum is σ = 237828960. Its totient is φ = 71348544.

The previous prime is 133778647. The next prime is 133778657. The reversal of 133778655 is 556877331.

It is not a de Polignac number, because 133778655 - 2³ = 133778647 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 133778655.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133778657) 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 15 ways as a sum of consecutive naturals, for example, 495342 + ... + 495611.

It is an arithmetic number, because the mean of its divisors is an integer number (14864310).

Almost surely, 2^133778655 is an apocalyptic number.

133778655 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

133778655 is a deficient number, since it is larger than the sum of its proper divisors (104050305).

133778655 is an equidigital number, since it uses as much as digits as its factorization.

133778655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 990967 (or 990961 counting only the distinct ones).

The product of its digits is 529200, while the sum is 45.

The square root of 133778655 is about 11566.2723035557. The cubic root of 133778655 is about 511.4410798912.

Adding to 133778655 its product of digits (529200), we get a triangular number (134307855 = T₁₆₃₈₉).

The spelling of 133778655 in words is "one hundred thirty-three million, seven hundred seventy-eight thousand, six hundred fifty-five".