661576603 has 2 divisors, whose sum is σ = 661576604. Its totient is φ = 661576602.

The previous prime is 661576583. The next prime is 661576609. The reversal of 661576603 is 306675166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661576603 - 2¹⁷ = 661445531 is a prime.

It is not a weakly prime, because it can be changed into another prime (661576609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330788301 + 330788302.

It is an arithmetic number, because the mean of its divisors is an integer number (330788302).

Almost surely, 2^661576603 is an apocalyptic number.

661576603 is a deficient number, since it is larger than the sum of its proper divisors (1).

661576603 is an equidigital number, since it uses as much as digits as its factorization.

661576603 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 136080, while the sum is 40.

The square root of 661576603 is about 25721.1314486746. The cubic root of 661576603 is about 871.3514921765.

The spelling of 661576603 in words is "six hundred sixty-one million, five hundred seventy-six thousand, six hundred three".