661015633 has 2 divisors, whose sum is σ = 661015634. Its totient is φ = 661015632.

The previous prime is 661015603. The next prime is 661015639. The reversal of 661015633 is 336510166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 357663744 + 303351889 = 18912^2 + 17417^2 .

It is a cyclic number.

It is not a de Polignac number, because 661015633 - 2¹⁷ = 660884561 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 661015595 and 661015604.

It is not a weakly prime, because it can be changed into another prime (661015639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330507816 + 330507817.

It is an arithmetic number, because the mean of its divisors is an integer number (330507817).

Almost surely, 2^661015633 is an apocalyptic number.

It is an amenable number.

661015633 is a deficient number, since it is larger than the sum of its proper divisors (1).

661015633 is an equidigital number, since it uses as much as digits as its factorization.

661015633 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 31.

The square root of 661015633 is about 25710.2242891811. The cubic root of 661015633 is about 871.1051411287.

Adding to 661015633 its reverse (336510166), we get a palindrome (997525799).

The spelling of 661015633 in words is "six hundred sixty-one million, fifteen thousand, six hundred thirty-three".