39427800381821 has 2 divisors, whose sum is σ = 39427800381822. Its totient is φ = 39427800381820.

The previous prime is 39427800381793. The next prime is 39427800381839. The reversal of 39427800381821 is 12818300872493.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24135711921721 + 15292088460100 = 4912811^2 + 3910510^2 .

It is an emirp because it is prime and its reverse (12818300872493) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39427800381821 - 2³⁰ = 39426726639997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39427800381841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19713900190910 + 19713900190911.

It is an arithmetic number, because the mean of its divisors is an integer number (19713900190911).

Almost surely, 2^{39427800381821} is an apocalyptic number.

It is an amenable number.

39427800381821 is a deficient number, since it is larger than the sum of its proper divisors (1).

39427800381821 is an equidigital number, since it uses as much as digits as its factorization.

39427800381821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4644864, while the sum is 56.

The spelling of 39427800381821 in words is "thirty-nine trillion, four hundred twenty-seven billion, eight hundred million, three hundred eighty-one thousand, eight hundred twenty-one".