81013506 has 32 divisors (see below), whose sum is σ = 185518080. Its totient is φ = 23103696.

The previous prime is 81013489. The next prime is 81013507. The reversal of 81013506 is 60531018.

It is not an unprimeable number, because it can be changed into a prime (81013507) 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, 26215 + ... + 29141.

It is an arithmetic number, because the mean of its divisors is an integer number (5797440).

Almost surely, 2^81013506 is an apocalyptic number.

81013506 is an abundant number, since it is smaller than the sum of its proper divisors (104504574).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81013506 is a wasteful number, since it uses less digits than its factorization.

81013506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3598.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 81013506 is about 9000.7503020582. The cubic root of 81013506 is about 432.6989179319.

The spelling of 81013506 in words is "eighty-one million, thirteen thousand, five hundred six".