19972409893 has 2 divisors, whose sum is σ = 19972409894. Its totient is φ = 19972409892.

The previous prime is 19972409887. The next prime is 19972409953. The reversal of 19972409893 is 39890427991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18496544004 + 1475865889 = 136002^2 + 38417^2 .

It is a cyclic number.

It is not a de Polignac number, because 19972409893 - 2⁹ = 19972409381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19972409803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9986204946 + 9986204947.

It is an arithmetic number, because the mean of its divisors is an integer number (9986204947).

Almost surely, 2^19972409893 is an apocalyptic number.

It is an amenable number.

19972409893 is a deficient number, since it is larger than the sum of its proper divisors (1).

19972409893 is an equidigital number, since it uses as much as digits as its factorization.

19972409893 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8817984, while the sum is 61.

The spelling of 19972409893 in words is "nineteen billion, nine hundred seventy-two million, four hundred nine thousand, eight hundred ninety-three".