1161377881 has 2 divisors, whose sum is σ = 1161377882. Its totient is φ = 1161377880.

The previous prime is 1161377879. The next prime is 1161377909. The reversal of 1161377881 is 1887731611.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 840072256 + 321305625 = 28984^2 + 17925^2 .

It is a cyclic number.

It is not a de Polignac number, because 1161377881 - 2¹ = 1161377879 is a prime.

It is a super-2 number, since 2×1161377881² = 2697597164952100322, which contains 22 as substring.

Together with 1161377879, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1161377681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 580688940 + 580688941.

It is an arithmetic number, because the mean of its divisors is an integer number (580688941).

Almost surely, 2^1161377881 is an apocalyptic number.

It is an amenable number.

1161377881 is a deficient number, since it is larger than the sum of its proper divisors (1).

1161377881 is an equidigital number, since it uses as much as digits as its factorization.

1161377881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56448, while the sum is 43.

The square root of 1161377881 is about 34078.9947181545. The cubic root of 1161377881 is about 1051.1334339608.

The spelling of 1161377881 in words is "one billion, one hundred sixty-one million, three hundred seventy-seven thousand, eight hundred eighty-one".