133720531 has 4 divisors (see below), whose sum is σ = 152823472. Its totient is φ = 114617592.

The previous prime is 133720513. The next prime is 133720547. The reversal of 133720531 is 135027331.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 135027331 = 229 ⋅589639.

It is a cyclic number.

It is not a de Polignac number, because 133720531 - 2⁷ = 133720403 is a prime.

It is a super-2 number, since 2×133720531² = 35762360821843922, 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 = 133720496 and 133720505.

It is not an unprimeable number, because it can be changed into a prime (133720571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9551460 + ... + 9551473.

It is an arithmetic number, because the mean of its divisors is an integer number (38205868).

Almost surely, 2^133720531 is an apocalyptic number.

133720531 is a deficient number, since it is larger than the sum of its proper divisors (19102941).

133720531 is an equidigital number, since it uses as much as digits as its factorization.

133720531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19102940.

The product of its (nonzero) digits is 1890, while the sum is 25.

The square root of 133720531 is about 11563.7593800632. The cubic root of 133720531 is about 511.3669990457.

Adding to 133720531 its reverse (135027331), we get a palindrome (268747862).

The spelling of 133720531 in words is "one hundred thirty-three million, seven hundred twenty thousand, five hundred thirty-one".