66013732709 has 2 divisors, whose sum is σ = 66013732710. Its totient is φ = 66013732708.

The previous prime is 66013732649. The next prime is 66013732721. The reversal of 66013732709 is 90723731066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38542327684 + 27471405025 = 196322^2 + 165745^2 .

It is a cyclic number.

It is not a de Polignac number, because 66013732709 - 2³² = 61718765413 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66013732709.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66013735709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33006866354 + 33006866355.

It is an arithmetic number, because the mean of its divisors is an integer number (33006866355).

Almost surely, 2^66013732709 is an apocalyptic number.

It is an amenable number.

66013732709 is a deficient number, since it is larger than the sum of its proper divisors (1).

66013732709 is an equidigital number, since it uses as much as digits as its factorization.

66013732709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 285768, while the sum is 44.

The spelling of 66013732709 in words is "sixty-six billion, thirteen million, seven hundred thirty-two thousand, seven hundred nine".