81011715 has 16 divisors (see below), whose sum is σ = 137243808. Its totient is φ = 40664576.

The previous prime is 81011713. The next prime is 81011717. The reversal of 81011715 is 51711018.

It is an interprime number because it is at equal distance from previous prime (81011713) and next prime (81011717).

It is a cyclic number.

It is not a de Polignac number, because 81011715 - 2¹ = 81011713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81011713) 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, 158592 + ... + 159101.

It is an arithmetic number, because the mean of its divisors is an integer number (8577738).

Almost surely, 2^81011715 is an apocalyptic number.

81011715 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

81011715 is a deficient number, since it is larger than the sum of its proper divisors (56232093).

81011715 is a wasteful number, since it uses less digits than its factorization.

81011715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 317718.

The product of its (nonzero) digits is 280, while the sum is 24.

The square root of 81011715 is about 9000.6508098026. The cubic root of 81011715 is about 432.6957292888.

The spelling of 81011715 in words is "eighty-one million, eleven thousand, seven hundred fifteen".