3799949016821 has 2 divisors, whose sum is σ = 3799949016822. Its totient is φ = 3799949016820.

The previous prime is 3799949016811. The next prime is 3799949016839. The reversal of 3799949016821 is 1286109499973.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2713432562500 + 1086516454321 = 1647250^2 + 1042361^2 .

It is an emirp because it is prime and its reverse (1286109499973) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3799949016821 is a prime.

It is a super-2 number, since 2×3799949016821² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3799949016811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1899974508410 + 1899974508411.

It is an arithmetic number, because the mean of its divisors is an integer number (1899974508411).

Almost surely, 2^{3799949016821} is an apocalyptic number.

It is an amenable number.

3799949016821 is a deficient number, since it is larger than the sum of its proper divisors (1).

3799949016821 is an equidigital number, since it uses as much as digits as its factorization.

3799949016821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52907904, while the sum is 68.

The spelling of 3799949016821 in words is "three trillion, seven hundred ninety-nine billion, nine hundred forty-nine million, sixteen thousand, eight hundred twenty-one".