661019 has 2 divisors, whose sum is σ = 661020. Its totient is φ = 661018.

The previous prime is 661009. The next prime is 661027. The reversal of 661019 is 910166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661019 - 2¹² = 656923 is a prime.

It is a super-2 number, since 2×661019² = 873892236722, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 660985 and 661003.

It is not a weakly prime, because it can be changed into another prime (661009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330509 + 330510.

It is an arithmetic number, because the mean of its divisors is an integer number (330510).

2⁶⁶¹⁰¹⁹ is an apocalyptic number.

661019 is a deficient number, since it is larger than the sum of its proper divisors (1).

661019 is an equidigital number, since it uses as much as digits as its factorization.

661019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 661019 is about 813.0307497260. The cubic root of 661019 is about 87.1106620169.

The spelling of 661019 in words is "six hundred sixty-one thousand, nineteen".