133781643 has 12 divisors (see below), whose sum is σ = 197734680. Its totient is φ = 87113376.

The previous prime is 133781629. The next prime is 133781651. The reversal of 133781643 is 346187331.

133781643 is a `hidden beast` number, since 1 + 3 + 3 + 7 + 8 + 1 + 643 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-133781643 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 133781598 and 133781607.

It is not an unprimeable number, because it can be changed into a prime (133781623) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 172458 + ... + 173231.

It is an arithmetic number, because the mean of its divisors is an integer number (16477890).

Almost surely, 2^133781643 is an apocalyptic number.

133781643 is a deficient number, since it is larger than the sum of its proper divisors (63953037).

133781643 is a wasteful number, since it uses less digits than its factorization.

133781643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 345738 (or 345735 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 133781643 is about 11566.4014715036. The cubic root of 133781643 is about 511.4448876101. Note that the first 3 decimals are identical.

The spelling of 133781643 in words is "one hundred thirty-three million, seven hundred eighty-one thousand, six hundred forty-three".