191261610749 has 24 divisors (see below), whose sum is σ = 217260551424. Its totient is φ = 168187192800.

The previous prime is 191261610739. The next prime is 191261610781. The reversal of 191261610749 is 947016162191.

It is a de Polignac number, because none of the positive numbers 2^k-191261610749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191261610739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 88833857 + ... + 88836009.

It is an arithmetic number, because the mean of its divisors is an integer number (9052522976).

Almost surely, 2^191261610749 is an apocalyptic number.

It is an amenable number.

191261610749 is a deficient number, since it is larger than the sum of its proper divisors (25998940675).

191261610749 is an frugal number, since it uses more digits than its factorization.

191261610749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4370 (or 2195 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 47.

The spelling of 191261610749 in words is "one hundred ninety-one billion, two hundred sixty-one million, six hundred ten thousand, seven hundred forty-nine".