81996015 has 16 divisors (see below), whose sum is σ = 138911328. Its totient is φ = 41158656.

The previous prime is 81996011. The next prime is 81996029. The reversal of 81996015 is 51069918.

It is not a de Polignac number, because 81996015 - 2² = 81996011 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81996011) 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, 160522 + ... + 161031.

It is an arithmetic number, because the mean of its divisors is an integer number (8681958).

Almost surely, 2^81996015 is an apocalyptic number.

81996015 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

81996015 is a deficient number, since it is larger than the sum of its proper divisors (56915313).

81996015 is a wasteful number, since it uses less digits than its factorization.

81996015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321578.

The product of its (nonzero) digits is 19440, while the sum is 39.

The square root of 81996015 is about 9055.1651006484. The cubic root of 81996015 is about 434.4411107561.

The spelling of 81996015 in words is "eighty-one million, nine hundred ninety-six thousand, fifteen".