18825413821 has 2 divisors, whose sum is σ = 18825413822. Its totient is φ = 18825413820.

The previous prime is 18825413729. The next prime is 18825413837. The reversal of 18825413821 is 12831452881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11462057721 + 7363356100 = 107061^2 + 85810^2 .

It is a cyclic number.

It is not a de Polignac number, because 18825413821 - 2¹⁹ = 18824889533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18825411821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9412706910 + 9412706911.

It is an arithmetic number, because the mean of its divisors is an integer number (9412706911).

Almost surely, 2^18825413821 is an apocalyptic number.

It is an amenable number.

18825413821 is a deficient number, since it is larger than the sum of its proper divisors (1).

18825413821 is an equidigital number, since it uses as much as digits as its factorization.

18825413821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 122880, while the sum is 43.

The spelling of 18825413821 in words is "eighteen billion, eight hundred twenty-five million, four hundred thirteen thousand, eight hundred twenty-one".