81902855 has 16 divisors (see below), whose sum is σ = 105390720. Its totient is φ = 60882432.

The previous prime is 81902833. The next prime is 81902881. The reversal of 81902855 is 55820918.

It is a cyclic number.

It is not a de Polignac number, because 81902855 - 2⁶ = 81902791 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 617 + ... + 12813.

It is an arithmetic number, because the mean of its divisors is an integer number (6586920).

Almost surely, 2^81902855 is an apocalyptic number.

81902855 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

81902855 is a deficient number, since it is larger than the sum of its proper divisors (23487865).

81902855 is a wasteful number, since it uses less digits than its factorization.

81902855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12298.

The product of its (nonzero) digits is 28800, while the sum is 38.

The square root of 81902855 is about 9050.0196132384. The cubic root of 81902855 is about 434.2765179149.

The spelling of 81902855 in words is "eighty-one million, nine hundred two thousand, eight hundred fifty-five".