39361697821 has 2 divisors, whose sum is σ = 39361697822. Its totient is φ = 39361697820.

The previous prime is 39361697819. The next prime is 39361697911. The reversal of 39361697821 is 12879616393.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36134208100 + 3227489721 = 190090^2 + 56811^2 .

It is a cyclic number.

It is not a de Polignac number, because 39361697821 - 2¹ = 39361697819 is a prime.

It is a super-2 number, since 2×39361697821² (a number of 22 digits) contains 22 as substring.

Together with 39361697819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39361697801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19680848910 + 19680848911.

It is an arithmetic number, because the mean of its divisors is an integer number (19680848911).

Almost surely, 2^39361697821 is an apocalyptic number.

It is an amenable number.

39361697821 is a deficient number, since it is larger than the sum of its proper divisors (1).

39361697821 is an equidigital number, since it uses as much as digits as its factorization.

39361697821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2939328, while the sum is 55.

The spelling of 39361697821 in words is "thirty-nine billion, three hundred sixty-one million, six hundred ninety-seven thousand, eight hundred twenty-one".