19180530821 has 2 divisors, whose sum is σ = 19180530822. Its totient is φ = 19180530820.

The previous prime is 19180530773. The next prime is 19180530841. The reversal of 19180530821 is 12803508191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18596776900 + 583753921 = 136370^2 + 24161^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19180530821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19180530841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9590265410 + 9590265411.

It is an arithmetic number, because the mean of its divisors is an integer number (9590265411).

Almost surely, 2^19180530821 is an apocalyptic number.

It is an amenable number.

19180530821 is a deficient number, since it is larger than the sum of its proper divisors (1).

19180530821 is an equidigital number, since it uses as much as digits as its factorization.

19180530821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 38.

The spelling of 19180530821 in words is "nineteen billion, one hundred eighty million, five hundred thirty thousand, eight hundred twenty-one".