81800151 has 4 divisors (see below), whose sum is σ = 109066872. Its totient is φ = 54533432.

The previous prime is 81800119. The next prime is 81800221. The reversal of 81800151 is 15100818.

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

It is a cyclic number.

It is not a de Polignac number, because 81800151 - 2⁵ = 81800119 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81800051) 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, 13633356 + ... + 13633361.

It is an arithmetic number, because the mean of its divisors is an integer number (27266718).

Almost surely, 2^81800151 is an apocalyptic number.

81800151 is a deficient number, since it is larger than the sum of its proper divisors (27266721).

81800151 is a wasteful number, since it uses less digits than its factorization.

81800151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27266720.

The product of its (nonzero) digits is 320, while the sum is 24.

The square root of 81800151 is about 9044.3435914388. The cubic root of 81800151 is about 434.0949182555.

Adding to 81800151 its reverse (15100818), we get a palindrome (96900969).

The spelling of 81800151 in words is "eighty-one million, eight hundred thousand, one hundred fifty-one".