661913533 has 4 divisors (see below), whose sum is σ = 662255100. Its totient is φ = 661571968.

The previous prime is 661913531. The next prime is 661913537. The reversal of 661913533 is 335319166.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 453775204 + 208138329 = 21302^2 + 14427^2 .

It is a cyclic number.

It is not a de Polignac number, because 661913533 - 2¹ = 661913531 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 661913492 and 661913501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661913531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 167860 + ... + 171757.

It is an arithmetic number, because the mean of its divisors is an integer number (165563775).

Almost surely, 2^661913533 is an apocalyptic number.

It is an amenable number.

661913533 is a deficient number, since it is larger than the sum of its proper divisors (341567).

661913533 is a wasteful number, since it uses less digits than its factorization.

661913533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 341566.

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

The square root of 661913533 is about 25727.6802879700. The cubic root of 661913533 is about 871.4993886972.

The spelling of 661913533 in words is "six hundred sixty-one million, nine hundred thirteen thousand, five hundred thirty-three".