661930523 has 2 divisors, whose sum is σ = 661930524. Its totient is φ = 661930522.

The previous prime is 661930471. The next prime is 661930541. The reversal of 661930523 is 325039166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661930523 - 2⁸ = 661930267 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (661900523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330965261 + 330965262.

It is an arithmetic number, because the mean of its divisors is an integer number (330965262).

Almost surely, 2^661930523 is an apocalyptic number.

661930523 is a deficient number, since it is larger than the sum of its proper divisors (1).

661930523 is an equidigital number, since it uses as much as digits as its factorization.

661930523 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 29160, while the sum is 35.

The square root of 661930523 is about 25728.0104749668. The cubic root of 661930523 is about 871.5068451836.

Adding to 661930523 its reverse (325039166), we get a palindrome (986969689).

The spelling of 661930523 in words is "six hundred sixty-one million, nine hundred thirty thousand, five hundred twenty-three".