81380015 has 8 divisors (see below), whose sum is σ = 97796160. Its totient is φ = 65010592.

The previous prime is 81380011. The next prime is 81380029. The reversal of 81380015 is 51008318.

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 81380015 - 2² = 81380011 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81380011) 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, 7724 + ... + 14913.

It is an arithmetic number, because the mean of its divisors is an integer number (12224520).

Almost surely, 2^81380015 is an apocalyptic number.

81380015 is a deficient number, since it is larger than the sum of its proper divisors (16416145).

81380015 is a wasteful number, since it uses less digits than its factorization.

81380015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23361.

The product of its (nonzero) digits is 960, while the sum is 26.

The square root of 81380015 is about 9021.0872404605. The cubic root of 81380015 is about 433.3504533013.

The spelling of 81380015 in words is "eighty-one million, three hundred eighty thousand, fifteen".