661066619 has 2 divisors, whose sum is σ = 661066620. Its totient is φ = 661066618.

The previous prime is 661066613. The next prime is 661066631. The reversal of 661066619 is 916660166.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661066619 - 2⁴ = 661066603 is a prime.

It is a super-2 number, since 2×661066619² = 874018149512182322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (661066613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330533309 + 330533310.

It is an arithmetic number, because the mean of its divisors is an integer number (330533310).

Almost surely, 2^661066619 is an apocalyptic number.

661066619 is a deficient number, since it is larger than the sum of its proper divisors (1).

661066619 is an equidigital number, since it uses as much as digits as its factorization.

661066619 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 41.

The square root of 661066619 is about 25711.2158211159. The cubic root of 661066619 is about 871.1275374850.

The spelling of 661066619 in words is "six hundred sixty-one million, sixty-six thousand, six hundred nineteen".