661015361 has 2 divisors, whose sum is σ = 661015362. Its totient is φ = 661015360.

The previous prime is 661015351. The next prime is 661015363. The reversal of 661015361 is 163510166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 444366400 + 216648961 = 21080^2 + 14719^2 .

It is a cyclic number.

It is not a de Polignac number, because 661015361 - 2¹⁰ = 661014337 is a prime.

Together with 661015363, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (661015363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330507680 + 330507681.

It is an arithmetic number, because the mean of its divisors is an integer number (330507681).

Almost surely, 2^661015361 is an apocalyptic number.

It is an amenable number.

661015361 is a deficient number, since it is larger than the sum of its proper divisors (1).

661015361 is an equidigital number, since it uses as much as digits as its factorization.

661015361 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 661015361 is about 25710.2189994562. The cubic root of 661015361 is about 871.1050216456.

The spelling of 661015361 in words is "six hundred sixty-one million, fifteen thousand, three hundred sixty-one".