661115633 has 2 divisors, whose sum is σ = 661115634. Its totient is φ = 661115632.

The previous prime is 661115573. The next prime is 661115647. The reversal of 661115633 is 336511166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 660901264 + 214369 = 25708^2 + 463^2 .

It is a cyclic number.

It is not a de Polignac number, because 661115633 - 2⁶ = 661115569 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 661115633.

It is not a weakly prime, because it can be changed into another prime (661115683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330557816 + 330557817.

It is an arithmetic number, because the mean of its divisors is an integer number (330557817).

Almost surely, 2^661115633 is an apocalyptic number.

It is an amenable number.

661115633 is a deficient number, since it is larger than the sum of its proper divisors (1).

661115633 is an equidigital number, since it uses as much as digits as its factorization.

661115633 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9720, while the sum is 32.

The square root of 661115633 is about 25712.1689672420. The cubic root of 661115633 is about 871.1490665254.

Adding to 661115633 its reverse (336511166), we get a palindrome (997626799).

The spelling of 661115633 in words is "six hundred sixty-one million, one hundred fifteen thousand, six hundred thirty-three".