81895951 has 16 divisors (see below), whose sum is σ = 85900320. Its totient is φ = 78019200.

The previous prime is 81895943. The next prime is 81895963. The reversal of 81895951 is 15959818.

It is not a de Polignac number, because 81895951 - 2³ = 81895943 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81895921) 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, 473301 + ... + 473473.

It is an arithmetic number, because the mean of its divisors is an integer number (5368770).

Almost surely, 2^81895951 is an apocalyptic number.

81895951 is a deficient number, since it is larger than the sum of its proper divisors (4004369).

81895951 is a wasteful number, since it uses less digits than its factorization.

81895951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426.

The product of its digits is 129600, while the sum is 46.

The square root of 81895951 is about 9049.6381695624. The cubic root of 81895951 is about 434.2643151277.

It can be divided in two parts, 818 and 95951, that added together give a palindrome (96769).

The spelling of 81895951 in words is "eighty-one million, eight hundred ninety-five thousand, nine hundred fifty-one".