81015427209 has 8 divisors (see below), whose sum is σ = 111745416960. Its totient is φ = 52147861136.

The previous prime is 81015427201. The next prime is 81015427231. The reversal of 81015427209 is 90272451018.

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 81015427209 - 2³ = 81015427201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81015427201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 465605817 + ... + 465605990.

It is an arithmetic number, because the mean of its divisors is an integer number (13968177120).

Almost surely, 2^81015427209 is an apocalyptic number.

It is an amenable number.

81015427209 is a deficient number, since it is larger than the sum of its proper divisors (30729989751).

81015427209 is a wasteful number, since it uses less digits than its factorization.

81015427209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 931211839.

The product of its (nonzero) digits is 40320, while the sum is 39.

The spelling of 81015427209 in words is "eighty-one billion, fifteen million, four hundred twenty-seven thousand, two hundred nine".