81356151 has 4 divisors (see below), whose sum is σ = 108474872. Its totient is φ = 54237432.

The previous prime is 81356147. The next prime is 81356153. The reversal of 81356151 is 15165318.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 81356151 - 2² = 81356147 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81356153) 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, 13559356 + ... + 13559361.

It is an arithmetic number, because the mean of its divisors is an integer number (27118718).

Almost surely, 2^81356151 is an apocalyptic number.

81356151 is a deficient number, since it is larger than the sum of its proper divisors (27118721).

81356151 is a wasteful number, since it uses less digits than its factorization.

81356151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27118720.

The product of its digits is 3600, while the sum is 30.

The square root of 81356151 is about 9019.7644647740. The cubic root of 81356151 is about 433.3080903770.

The spelling of 81356151 in words is "eighty-one million, three hundred fifty-six thousand, one hundred fifty-one".