19797149381 has 2 divisors, whose sum is σ = 19797149382. Its totient is φ = 19797149380.

The previous prime is 19797149369. The next prime is 19797149387. The reversal of 19797149381 is 18394179791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14656976356 + 5140173025 = 121066^2 + 71695^2 .

It is a cyclic number.

It is not a de Polignac number, because 19797149381 - 2¹⁴ = 19797132997 is a prime.

It is a super-2 number, since 2×19797149381² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 19797149381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19797149387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9898574690 + 9898574691.

It is an arithmetic number, because the mean of its divisors is an integer number (9898574691).

Almost surely, 2^19797149381 is an apocalyptic number.

It is an amenable number.

19797149381 is a deficient number, since it is larger than the sum of its proper divisors (1).

19797149381 is an equidigital number, since it uses as much as digits as its factorization.

19797149381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3429216, while the sum is 59.

The spelling of 19797149381 in words is "nineteen billion, seven hundred ninety-seven million, one hundred forty-nine thousand, three hundred eighty-one".