191464817381 has 2 divisors, whose sum is σ = 191464817382. Its totient is φ = 191464817380.

The previous prime is 191464817351. The next prime is 191464817413. The reversal of 191464817381 is 183718464191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 124562408356 + 66902409025 = 352934^2 + 258655^2 .

It is a cyclic number.

It is not a de Polignac number, because 191464817381 - 2¹⁴ = 191464800997 is a prime.

It is a super-2 number, since 2×191464817381² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191464817351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95732408690 + 95732408691.

It is an arithmetic number, because the mean of its divisors is an integer number (95732408691).

Almost surely, 2^191464817381 is an apocalyptic number.

It is an amenable number.

191464817381 is a deficient number, since it is larger than the sum of its proper divisors (1).

191464817381 is an equidigital number, since it uses as much as digits as its factorization.

191464817381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1161216, while the sum is 53.

The spelling of 191464817381 in words is "one hundred ninety-one billion, four hundred sixty-four million, eight hundred seventeen thousand, three hundred eighty-one".