19400478997 has 2 divisors, whose sum is σ = 19400478998. Its totient is φ = 19400478996.

The previous prime is 19400478973. The next prime is 19400479009. The reversal of 19400478997 is 79987400491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17316191281 + 2084287716 = 131591^2 + 45654^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19400478997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19400478967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9700239498 + 9700239499.

It is an arithmetic number, because the mean of its divisors is an integer number (9700239499).

Almost surely, 2^19400478997 is an apocalyptic number.

It is an amenable number.

19400478997 is a deficient number, since it is larger than the sum of its proper divisors (1).

19400478997 is an equidigital number, since it uses as much as digits as its factorization.

19400478997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4572288, while the sum is 58.

The spelling of 19400478997 in words is "nineteen billion, four hundred million, four hundred seventy-eight thousand, nine hundred ninety-seven".