81127961 has 16 divisors (see below), whose sum is σ = 89164800. Its totient is φ = 73482240.

The previous prime is 81127957. The next prime is 81127999. The reversal of 81127961 is 16972118.

It is a cyclic number.

It is not a de Polignac number, because 81127961 - 2² = 81127957 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 (81127901) 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, 135140 + ... + 135738.

It is an arithmetic number, because the mean of its divisors is an integer number (5572800).

Almost surely, 2^81127961 is an apocalyptic number.

It is an amenable number.

81127961 is a deficient number, since it is larger than the sum of its proper divisors (8036839).

81127961 is a wasteful number, since it uses less digits than its factorization.

81127961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 904.

The product of its digits is 6048, while the sum is 35.

The square root of 81127961 is about 9007.1061390438. The cubic root of 81127961 is about 432.9025928202.

The spelling of 81127961 in words is "eighty-one million, one hundred twenty-seven thousand, nine hundred sixty-one".