191389956469 has 2 divisors, whose sum is σ = 191389956470. Its totient is φ = 191389956468.

The previous prime is 191389956431. The next prime is 191389956521. The reversal of 191389956469 is 964659983191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 191373876369 + 16080100 = 437463^2 + 4010^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191389956469 is a prime.

It is a super-2 number, since 2×191389956469² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 191389956398 and 191389956407.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191389956269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95694978234 + 95694978235.

It is an arithmetic number, because the mean of its divisors is an integer number (95694978235).

Almost surely, 2^191389956469 is an apocalyptic number.

It is an amenable number.

191389956469 is a deficient number, since it is larger than the sum of its proper divisors (1).

191389956469 is an equidigital number, since it uses as much as digits as its factorization.

191389956469 is an evil number, because the sum of its binary digits is even.

The product of its digits is 113374080, while the sum is 70.

The spelling of 191389956469 in words is "one hundred ninety-one billion, three hundred eighty-nine million, nine hundred fifty-six thousand, four hundred sixty-nine".