19930489021 has 2 divisors, whose sum is σ = 19930489022. Its totient is φ = 19930489020.

The previous prime is 19930489013. The next prime is 19930489063. The reversal of 19930489021 is 12098403991.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19397525625 + 532963396 = 139275^2 + 23086^2 .

It is a cyclic number.

It is not a de Polignac number, because 19930489021 - 2³ = 19930489013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19930489721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9965244510 + 9965244511.

It is an arithmetic number, because the mean of its divisors is an integer number (9965244511).

Almost surely, 2^19930489021 is an apocalyptic number.

It is an amenable number.

19930489021 is a deficient number, since it is larger than the sum of its proper divisors (1).

19930489021 is an equidigital number, since it uses as much as digits as its factorization.

19930489021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 139968, while the sum is 46.

The spelling of 19930489021 in words is "nineteen billion, nine hundred thirty million, four hundred eighty-nine thousand, twenty-one".