19908400793 has 2 divisors, whose sum is σ = 19908400794. Its totient is φ = 19908400792.

The previous prime is 19908400769. The next prime is 19908400807. The reversal of 19908400793 is 39700480991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16107924889 + 3800475904 = 126917^2 + 61648^2 .

It is a cyclic number.

It is not a de Polignac number, because 19908400793 - 2¹⁶ = 19908335257 is a prime.

It is not a weakly prime, because it can be changed into another prime (19908400763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9954200396 + 9954200397.

It is an arithmetic number, because the mean of its divisors is an integer number (9954200397).

Almost surely, 2^19908400793 is an apocalyptic number.

It is an amenable number.

19908400793 is a deficient number, since it is larger than the sum of its proper divisors (1).

19908400793 is an equidigital number, since it uses as much as digits as its factorization.

19908400793 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 489888, while the sum is 50.

The spelling of 19908400793 in words is "nineteen billion, nine hundred eight million, four hundred thousand, seven hundred ninety-three".