661612267 has 2 divisors, whose sum is σ = 661612268. Its totient is φ = 661612266.

The previous prime is 661612249. The next prime is 661612271. The reversal of 661612267 is 762216166.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661612267 - 2⁷ = 661612139 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (661612247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330806133 + 330806134.

It is an arithmetic number, because the mean of its divisors is an integer number (330806134).

Almost surely, 2^661612267 is an apocalyptic number.

661612267 is a deficient number, since it is larger than the sum of its proper divisors (1).

661612267 is an equidigital number, since it uses as much as digits as its factorization.

661612267 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 37.

The square root of 661612267 is about 25721.8247214306. The cubic root of 661612267 is about 871.3671493814.

The spelling of 661612267 in words is "six hundred sixty-one million, six hundred twelve thousand, two hundred sixty-seven".