661612603 has 2 divisors, whose sum is σ = 661612604. Its totient is φ = 661612602.

The previous prime is 661612591. The next prime is 661612619. The reversal of 661612603 is 306216166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661612603 - 2²⁹ = 124741691 is a prime.

It is not a weakly prime, because it can be changed into another prime (661612643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330806301 + 330806302.

It is an arithmetic number, because the mean of its divisors is an integer number (330806302).

Almost surely, 2^661612603 is an apocalyptic number.

661612603 is a deficient number, since it is larger than the sum of its proper divisors (1).

661612603 is an equidigital number, since it uses as much as digits as its factorization.

661612603 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 661612603 is about 25721.8312528482. The cubic root of 661612603 is about 871.3672968894.

Adding to 661612603 its reverse (306216166), we get a palindrome (967828769).

The spelling of 661612603 in words is "six hundred sixty-one million, six hundred twelve thousand, six hundred three".