661625267 has 2 divisors, whose sum is σ = 661625268. Its totient is φ = 661625266.

The previous prime is 661625249. The next prime is 661625311. The reversal of 661625267 is 762526166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661625267 - 2⁶ = 661625203 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (661621267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330812633 + 330812634.

It is an arithmetic number, because the mean of its divisors is an integer number (330812634).

Almost surely, 2^661625267 is an apocalyptic number.

661625267 is a deficient number, since it is larger than the sum of its proper divisors (1).

661625267 is an equidigital number, since it uses as much as digits as its factorization.

661625267 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 181440, while the sum is 41.

The square root of 661625267 is about 25722.0774238785. The cubic root of 661625267 is about 871.3728564999.

The spelling of 661625267 in words is "six hundred sixty-one million, six hundred twenty-five thousand, two hundred sixty-seven".