39661120813 has 2 divisors, whose sum is σ = 39661120814. Its totient is φ = 39661120812.

The previous prime is 39661120789. The next prime is 39661120823. The reversal of 39661120813 is 31802116693.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33628957924 + 6032162889 = 183382^2 + 77667^2 .

It is a cyclic number.

It is not a de Polignac number, because 39661120813 - 2¹⁷ = 39660989741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39661120823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19830560406 + 19830560407.

It is an arithmetic number, because the mean of its divisors is an integer number (19830560407).

Almost surely, 2^39661120813 is an apocalyptic number.

It is an amenable number.

39661120813 is a deficient number, since it is larger than the sum of its proper divisors (1).

39661120813 is an equidigital number, since it uses as much as digits as its factorization.

39661120813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 40.

The spelling of 39661120813 in words is "thirty-nine billion, six hundred sixty-one million, one hundred twenty thousand, eight hundred thirteen".