81308151 has 32 divisors (see below), whose sum is σ = 126397440. Its totient is φ = 51559200.

The previous prime is 81308137. The next prime is 81308173. The reversal of 81308151 is 15180318.

It is not a de Polignac number, because 81308151 - 2⁵ = 81308119 is a prime.

It is a super-2 number, since 2×81308151² = 13222030838077602, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81308111) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 192921 + ... + 193341.

It is an arithmetic number, because the mean of its divisors is an integer number (3949920).

Almost surely, 2^81308151 is an apocalyptic number.

81308151 is a deficient number, since it is larger than the sum of its proper divisors (45089289).

81308151 is a wasteful number, since it uses less digits than its factorization.

81308151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 764 (or 758 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 27.

The square root of 81308151 is about 9017.1032488266. The cubic root of 81308151 is about 433.2228565836. Note that the first 3 decimals are identical.

Adding to 81308151 its reverse (15180318), we get a palindrome (96488469).

The spelling of 81308151 in words is "eighty-one million, three hundred eight thousand, one hundred fifty-one".