81150905 has 16 divisors (see below), whose sum is σ = 108497664. Its totient is φ = 57761280.

The previous prime is 81150893. The next prime is 81150907. The reversal of 81150905 is 50905118.

It is not a de Polignac number, because 81150905 - 2⁴ = 81150889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81150907) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13112 + ... + 18281.

It is an arithmetic number, because the mean of its divisors is an integer number (6781104).

Almost surely, 2^81150905 is an apocalyptic number.

It is an amenable number.

81150905 is a deficient number, since it is larger than the sum of its proper divisors (27346759).

81150905 is a wasteful number, since it uses less digits than its factorization.

81150905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31456.

The product of its (nonzero) digits is 1800, while the sum is 29.

The square root of 81150905 is about 9008.3797100255. The cubic root of 81150905 is about 432.9433990592.

The spelling of 81150905 in words is "eighty-one million, one hundred fifty thousand, nine hundred five".