661324919 has 2 divisors, whose sum is σ = 661324920. Its totient is φ = 661324918.

The previous prime is 661324901. The next prime is 661324927. The reversal of 661324919 is 919423166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661324919 - 2¹² = 661320823 is a prime.

It is a super-3 number, since 3×661324919³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661324969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330662459 + 330662460.

It is an arithmetic number, because the mean of its divisors is an integer number (330662460).

Almost surely, 2^661324919 is an apocalyptic number.

661324919 is a deficient number, since it is larger than the sum of its proper divisors (1).

661324919 is an equidigital number, since it uses as much as digits as its factorization.

661324919 is an evil number, because the sum of its binary digits is even.

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

The square root of 661324919 is about 25716.2384302215. The cubic root of 661324919 is about 871.2409818975.

The spelling of 661324919 in words is "six hundred sixty-one million, three hundred twenty-four thousand, nine hundred nineteen".