81131051 has 8 divisors (see below), whose sum is σ = 85307904. Its totient is φ = 77008360.

The previous prime is 81131041. The next prime is 81131081. The reversal of 81131051 is 15013118.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81131051 - 2²⁶ = 14022187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81131041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10451 + ... + 16476.

It is an arithmetic number, because the mean of its divisors is an integer number (10663488).

Almost surely, 2^81131051 is an apocalyptic number.

81131051 is a deficient number, since it is larger than the sum of its proper divisors (4176853).

81131051 is a wasteful number, since it uses less digits than its factorization.

81131051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27081.

The product of its (nonzero) digits is 120, while the sum is 20.

The square root of 81131051 is about 9007.2776686411. The cubic root of 81131051 is about 432.9080888786.

Adding to 81131051 its reverse (15013118), we get a palindrome (96144169).

The spelling of 81131051 in words is "eighty-one million, one hundred thirty-one thousand, fifty-one".