660881213 has 2 divisors, whose sum is σ = 660881214. Its totient is φ = 660881212.

The previous prime is 660881197. The next prime is 660881293. The reversal of 660881213 is 312188066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 601868089 + 59013124 = 24533^2 + 7682^2 .

It is a cyclic number.

It is not a de Polignac number, because 660881213 - 2⁴ = 660881197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660881293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330440606 + 330440607.

It is an arithmetic number, because the mean of its divisors is an integer number (330440607).

Almost surely, 2^660881213 is an apocalyptic number.

It is an amenable number.

660881213 is a deficient number, since it is larger than the sum of its proper divisors (1).

660881213 is an equidigital number, since it uses as much as digits as its factorization.

660881213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 660881213 is about 25707.6100211591. The cubic root of 660881213 is about 871.0460896301.

The spelling of 660881213 in words is "six hundred sixty million, eight hundred eighty-one thousand, two hundred thirteen".