19497403735891 has 2 divisors, whose sum is σ = 19497403735892. Its totient is φ = 19497403735890.

The previous prime is 19497403735811. The next prime is 19497403735951. The reversal of 19497403735891 is 19853730479491.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19497403735891 - 2²⁵ = 19497370181459 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19497403735891.

It is not a weakly prime, because it can be changed into another prime (19497403735811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9748701867945 + 9748701867946.

It is an arithmetic number, because the mean of its divisors is an integer number (9748701867946).

Almost surely, 2^{19497403735891} is an apocalyptic number.

19497403735891 is a deficient number, since it is larger than the sum of its proper divisors (1).

19497403735891 is an equidigital number, since it uses as much as digits as its factorization.

19497403735891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 205752960, while the sum is 70.

The spelling of 19497403735891 in words is "nineteen trillion, four hundred ninety-seven billion, four hundred three million, seven hundred thirty-five thousand, eight hundred ninety-one".