1161255761 has 4 divisors (see below), whose sum is σ = 1163132400. Its totient is φ = 1159379124.

The previous prime is 1161255757. The next prime is 1161255779. The reversal of 1161255761 is 1675521611.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1161255761 - 2² = 1161255757 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1161257761) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 937391 + ... + 938628.

It is an arithmetic number, because the mean of its divisors is an integer number (290783100).

Almost surely, 2^1161255761 is an apocalyptic number.

It is an amenable number.

1161255761 is a deficient number, since it is larger than the sum of its proper divisors (1876639).

1161255761 is an equidigital number, since it uses as much as digits as its factorization.

1161255761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1876638.

The product of its digits is 12600, while the sum is 35.

The square root of 1161255761 is about 34077.2029515334. The cubic root of 1161255761 is about 1051.0965901059.

The spelling of 1161255761 in words is "one billion, one hundred sixty-one million, two hundred fifty-five thousand, seven hundred sixty-one".