81962881 has 32 divisors (see below), whose sum is σ = 113073408. Its totient is φ = 57335040.

The previous prime is 81962873. The next prime is 81962891. The reversal of 81962881 is 18826918.

It is not a de Polignac number, because 81962881 - 2³ = 81962873 is a prime.

It is a super-2 number, since 2×81962881² = 13435827723640322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81962801) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 35931 + ... + 38143.

It is an arithmetic number, because the mean of its divisors is an integer number (3533544).

Almost surely, 2^81962881 is an apocalyptic number.

It is an amenable number.

81962881 is a deficient number, since it is larger than the sum of its proper divisors (31110527).

81962881 is a wasteful number, since it uses less digits than its factorization.

81962881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2281.

The product of its digits is 55296, while the sum is 43.

The square root of 81962881 is about 9053.3353522335. The cubic root of 81962881 is about 434.3825846958.

The spelling of 81962881 in words is "eighty-one million, nine hundred sixty-two thousand, eight hundred eighty-one".