661246259 has 2 divisors, whose sum is σ = 661246260. Its totient is φ = 661246258.

The previous prime is 661246253. The next prime is 661246349. The reversal of 661246259 is 952642166.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661246259 - 2¹² = 661242163 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (661246253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330623129 + 330623130.

It is an arithmetic number, because the mean of its divisors is an integer number (330623130).

Almost surely, 2^661246259 is an apocalyptic number.

661246259 is a deficient number, since it is larger than the sum of its proper divisors (1).

661246259 is an equidigital number, since it uses as much as digits as its factorization.

661246259 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 41.

The square root of 661246259 is about 25714.7090008812. The cubic root of 661246259 is about 871.2064378426.

The spelling of 661246259 in words is "six hundred sixty-one million, two hundred forty-six thousand, two hundred fifty-nine".