81018121 has 8 divisors (see below), whose sum is σ = 84654720. Its totient is φ = 77391072.

The previous prime is 81018053. The next prime is 81018127. The reversal of 81018121 is 12181018.

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 81018121 - 2⁹ = 81017609 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 81018092 and 81018101.

It is not an unprimeable number, because it can be changed into a prime (81018127) 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, 19221 + ... + 23053.

It is an arithmetic number, because the mean of its divisors is an integer number (10581840).

Almost surely, 2^81018121 is an apocalyptic number.

It is an amenable number.

81018121 is a deficient number, since it is larger than the sum of its proper divisors (3636599).

81018121 is a wasteful number, since it uses less digits than its factorization.

81018121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4775.

The product of its (nonzero) digits is 128, while the sum is 22.

The square root of 81018121 is about 9001.0066659235. The cubic root of 81018121 is about 432.7071341240.

Adding to 81018121 its reverse (12181018), we get a palindrome (93199139).

The spelling of 81018121 in words is "eighty-one million, eighteen thousand, one hundred twenty-one".