133561631 has 4 divisors (see below), whose sum is σ = 152641872. Its totient is φ = 114481392.

The previous prime is 133561607. The next prime is 133561633. The reversal of 133561631 is 136165331.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 136165331 = 2423 ⋅56197.

It is a cyclic number.

It is not a de Polignac number, because 133561631 - 2²² = 129367327 is a prime.

It is a super-2 number, since 2×133561631² = 35677418550760322, 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 = 133561594 and 133561603.

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 3 ways as a sum of consecutive naturals, for example, 9540110 + ... + 9540123.

It is an arithmetic number, because the mean of its divisors is an integer number (38160468).

Almost surely, 2^133561631 is an apocalyptic number.

133561631 is a deficient number, since it is larger than the sum of its proper divisors (19080241).

133561631 is an equidigital number, since it uses as much as digits as its factorization.

133561631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19080240.

The product of its digits is 4860, while the sum is 29.

The square root of 133561631 is about 11556.8867347569. The cubic root of 133561631 is about 511.1643664298.

The spelling of 133561631 in words is "one hundred thirty-three million, five hundred sixty-one thousand, six hundred thirty-one".