81910315 has 4 divisors (see below), whose sum is σ = 98292384. Its totient is φ = 65528248.

The previous prime is 81910303. The next prime is 81910321. The reversal of 81910315 is 51301918.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81910315 - 2⁹ = 81909803 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8191027 + ... + 8191036.

It is an arithmetic number, because the mean of its divisors is an integer number (24573096).

Almost surely, 2^81910315 is an apocalyptic number.

81910315 is a deficient number, since it is larger than the sum of its proper divisors (16382069).

81910315 is a wasteful number, since it uses less digits than its factorization.

81910315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16382068.

The product of its (nonzero) digits is 1080, while the sum is 28.

The square root of 81910315 is about 9050.4317576566. The cubic root of 81910315 is about 434.2897026586.

The spelling of 81910315 in words is "eighty-one million, nine hundred ten thousand, three hundred fifteen".