661117799 has 2 divisors, whose sum is σ = 661117800. Its totient is φ = 661117798.

The previous prime is 661117783. The next prime is 661117801. The reversal of 661117799 is 997711166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661117799 - 2⁴ = 661117783 is a prime.

Together with 661117801, it forms a pair of twin primes.

It is a Chen prime.

It is a zygodrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661117099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330558899 + 330558900.

It is an arithmetic number, because the mean of its divisors is an integer number (330558900).

Almost surely, 2^661117799 is an apocalyptic number.

661117799 is a deficient number, since it is larger than the sum of its proper divisors (1).

661117799 is an equidigital number, since it uses as much as digits as its factorization.

661117799 is an evil number, because the sum of its binary digits is even.

The product of its digits is 142884, while the sum is 47.

The square root of 661117799 is about 25712.2110873414. The cubic root of 661117799 is about 871.1500179005.

The spelling of 661117799 in words is "six hundred sixty-one million, one hundred seventeen thousand, seven hundred ninety-nine".