9161127781 has 16 divisors (see below), whose sum is σ = 10432493568. Its totient is φ = 7984022400.

The previous prime is 9161127779. The next prime is 9161127791. The reversal of 9161127781 is 1877211619.

It is a cyclic number.

It is not a de Polignac number, because 9161127781 - 2¹ = 9161127779 is a prime.

It is a super-2 number, since 2×9161127781² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9161127791) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 260701 + ... + 293746.

It is an arithmetic number, because the mean of its divisors is an integer number (652030848).

Almost surely, 2^9161127781 is an apocalyptic number.

It is an amenable number.

9161127781 is a deficient number, since it is larger than the sum of its proper divisors (1271365787).

9161127781 is a wasteful number, since it uses less digits than its factorization.

9161127781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 554532.

The product of its digits is 42336, while the sum is 43.

The square root of 9161127781 is about 95713.7805177499. The cubic root of 9161127781 is about 2092.4237793969.

The spelling of 9161127781 in words is "nine billion, one hundred sixty-one million, one hundred twenty-seven thousand, seven hundred eighty-one".