661432783171 has 2 divisors, whose sum is σ = 661432783172. Its totient is φ = 661432783170.

The previous prime is 661432783049. The next prime is 661432783229. The reversal of 661432783171 is 171387234166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661432783171 - 2¹³ = 661432774979 is a prime.

It is not a weakly prime, because it can be changed into another prime (661432783871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330716391585 + 330716391586.

It is an arithmetic number, because the mean of its divisors is an integer number (330716391586).

Almost surely, 2^661432783171 is an apocalyptic number.

661432783171 is a deficient number, since it is larger than the sum of its proper divisors (1).

661432783171 is an equidigital number, since it uses as much as digits as its factorization.

661432783171 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1016064, while the sum is 49.

The spelling of 661432783171 in words is "six hundred sixty-one billion, four hundred thirty-two million, seven hundred eighty-three thousand, one hundred seventy-one".