133561639 has 12 divisors (see below), whose sum is σ = 144913824. Its totient is φ = 123017984.

The previous prime is 133561633. The next prime is 133561661. The reversal of 133561639 is 936165331.

It is not a de Polignac number, because 133561639 - 2⁵ = 133561607 is a prime.

It is a super-2 number, since 2×133561639² = 35677422824732642, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 133561598 and 133561607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133561633) 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, 8667 + ... + 18499.

It is an arithmetic number, because the mean of its divisors is an integer number (12076152).

Almost surely, 2^133561639 is an apocalyptic number.

133561639 is a deficient number, since it is larger than the sum of its proper divisors (11352185).

133561639 is an equidigital number, since it uses as much as digits as its factorization.

133561639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9914 (or 9897 counting only the distinct ones).

The product of its digits is 43740, while the sum is 37.

The square root of 133561639 is about 11556.8870808709. The cubic root of 133561639 is about 511.1643766356.

The spelling of 133561639 in words is "one hundred thirty-three million, five hundred sixty-one thousand, six hundred thirty-nine".