661899985319 has 2 divisors, whose sum is σ = 661899985320. Its totient is φ = 661899985318.

The previous prime is 661899985231. The next prime is 661899985337. The reversal of 661899985319 is 913589998166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661899985319 - 2²⁸ = 661631549863 is a prime.

It is a super-2 number, since 2×661899985319² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661899985399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330949992659 + 330949992660.

It is an arithmetic number, because the mean of its divisors is an integer number (330949992660).

Almost surely, 2^661899985319 is an apocalyptic number.

661899985319 is a deficient number, since it is larger than the sum of its proper divisors (1).

661899985319 is an equidigital number, since it uses as much as digits as its factorization.

661899985319 is an evil number, because the sum of its binary digits is even.

The product of its digits is 226748160, while the sum is 74.

The spelling of 661899985319 in words is "six hundred sixty-one billion, eight hundred ninety-nine million, nine hundred eighty-five thousand, three hundred nineteen".