135533561 has 16 divisors (see below), whose sum is σ = 142300800. Its totient is φ = 128988288.

The previous prime is 135533551. The next prime is 135533569. The reversal of 135533561 is 165335531.

It is a cyclic number.

It is not a de Polignac number, because 135533561 - 2¹⁸ = 135271417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (135533569) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 278060 + ... + 278546.

It is an arithmetic number, because the mean of its divisors is an integer number (8893800).

Almost surely, 2^135533561 is an apocalyptic number.

It is an amenable number.

135533561 is a deficient number, since it is larger than the sum of its proper divisors (6767239).

135533561 is an equidigital number, since it uses as much as digits as its factorization.

135533561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 688.

The product of its digits is 20250, while the sum is 32.

The square root of 135533561 is about 11641.8882059570. Note that the first 3 decimals coincide. The cubic root of 135533561 is about 513.6677300120.

The spelling of 135533561 in words is "one hundred thirty-five million, five hundred thirty-three thousand, five hundred sixty-one".