81963738 has 20 divisors (see below), whose sum is σ = 183659850. Its totient is φ = 27321192.

The previous prime is 81963727. The next prime is 81963751. The reversal of 81963738 is 83736918.

It is a happy number.

81963738 is a `hidden beast` number, since 8 + 1 + 9 + 637 + 3 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 45927729 + 36036009 = 6777^2 + 6003^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81963693 and 81963702.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 252813 + ... + 253136.

Almost surely, 2^81963738 is an apocalyptic number.

81963738 is an abundant number, since it is smaller than the sum of its proper divisors (101696112).

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

81963738 is a wasteful number, since it uses less digits than its factorization.

81963738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 505963 (or 505954 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 81963738 is about 9053.3826827325. The cubic root of 81963738 is about 434.3840986518.

The spelling of 81963738 in words is "eighty-one million, nine hundred sixty-three thousand, seven hundred thirty-eight".