38635751821 has 2 divisors, whose sum is σ = 38635751822. Its totient is φ = 38635751820.

The previous prime is 38635751789. The next prime is 38635751857. The reversal of 38635751821 is 12815753683.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 34428802500 + 4206949321 = 185550^2 + 64861^2 .

It is a cyclic number.

It is not a de Polignac number, because 38635751821 - 2⁵ = 38635751789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (38635757821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19317875910 + 19317875911.

It is an arithmetic number, because the mean of its divisors is an integer number (19317875911).

Almost surely, 2^38635751821 is an apocalyptic number.

It is an amenable number.

38635751821 is a deficient number, since it is larger than the sum of its proper divisors (1).

38635751821 is an equidigital number, since it uses as much as digits as its factorization.

38635751821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1209600, while the sum is 49.

The spelling of 38635751821 in words is "thirty-eight billion, six hundred thirty-five million, seven hundred fifty-one thousand, eight hundred twenty-one".