81212615 has 32 divisors (see below), whose sum is σ = 111974400. Its totient is φ = 55995520.

The previous prime is 81212603. The next prime is 81212623. The reversal of 81212615 is 51621218.

It is not a de Polignac number, because 81212615 - 2⁸ = 81212359 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 93674 + ... + 94536.

It is an arithmetic number, because the mean of its divisors is an integer number (3499200).

Almost surely, 2^81212615 is an apocalyptic number.

81212615 is a deficient number, since it is larger than the sum of its proper divisors (30761785).

81212615 is a wasteful number, since it uses less digits than its factorization.

81212615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 967.

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

The square root of 81212615 is about 9011.8042033768. The cubic root of 81212615 is about 433.0531130455.

The spelling of 81212615 in words is "eighty-one million, two hundred twelve thousand, six hundred fifteen".