81963936 has 72 divisors (see below), whose sum is σ = 246810564. Its totient is φ = 25712640.

The previous prime is 81963913. The next prime is 81963941. The reversal of 81963936 is 63936918.

81963936 is a `hidden beast` number, since 8 + 1 + 9 + 639 + 3 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 65610000 + 16353936 = 8100^2 + 4044^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×81963936² = 13436173609224192, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 81963891 and 81963900.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3475 + ... + 13266.

Almost surely, 2^81963936 is an apocalyptic number.

It is an amenable number.

81963936 is an abundant number, since it is smaller than the sum of its proper divisors (164846628).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81963936 is a wasteful number, since it uses less digits than its factorization.

81963936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16774 (or 16763 counting only the distinct ones).

The product of its digits is 209952, while the sum is 45.

The square root of 81963936 is about 9053.3936178651. The cubic root of 81963936 is about 434.3844484324.

The spelling of 81963936 in words is "eighty-one million, nine hundred sixty-three thousand, nine hundred thirty-six".