19400478973 has 2 divisors, whose sum is σ = 19400478974. Its totient is φ = 19400478972.

The previous prime is 19400478971. The next prime is 19400478997. The reversal of 19400478973 is 37987400491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18473702724 + 926776249 = 135918^2 + 30443^2 .

It is an emirp because it is prime and its reverse (37987400491) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19400478973 - 2¹ = 19400478971 is a prime.

Together with 19400478971, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 19400478973.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19400478971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9700239486 + 9700239487.

It is an arithmetic number, because the mean of its divisors is an integer number (9700239487).

Almost surely, 2^19400478973 is an apocalyptic number.

It is an amenable number.

19400478973 is a deficient number, since it is larger than the sum of its proper divisors (1).

19400478973 is an equidigital number, since it uses as much as digits as its factorization.

19400478973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1524096, while the sum is 52.

The spelling of 19400478973 in words is "nineteen billion, four hundred million, four hundred seventy-eight thousand, nine hundred seventy-three".