18713006821 has 2 divisors, whose sum is σ = 18713006822. Its totient is φ = 18713006820.

The previous prime is 18713006777. The next prime is 18713006827. The reversal of 18713006821 is 12860031781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14282640100 + 4430366721 = 119510^2 + 66561^2 .

It is a cyclic number.

It is not a de Polignac number, because 18713006821 - 2⁷ = 18713006693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18713006827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9356503410 + 9356503411.

It is an arithmetic number, because the mean of its divisors is an integer number (9356503411).

Almost surely, 2^18713006821 is an apocalyptic number.

It is an amenable number.

18713006821 is a deficient number, since it is larger than the sum of its proper divisors (1).

18713006821 is an equidigital number, since it uses as much as digits as its factorization.

18713006821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16128, while the sum is 37.

The spelling of 18713006821 in words is "eighteen billion, seven hundred thirteen million, six thousand, eight hundred twenty-one".