81263943 has 6 divisors (see below), whose sum is σ = 117381264. Its totient is φ = 54175956.

The previous prime is 81263939. The next prime is 81263993. The reversal of 81263943 is 34936218.

81263943 is a `hidden beast` number, since 8 + 12 + 639 + 4 + 3 = 666.

It is not a de Polignac number, because 81263943 - 2² = 81263939 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81263898 and 81263907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81263993) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4514655 + ... + 4514672.

It is an arithmetic number, because the mean of its divisors is an integer number (19563544).

Almost surely, 2^81263943 is an apocalyptic number.

81263943 is a deficient number, since it is larger than the sum of its proper divisors (36117321).

81263943 is a wasteful number, since it uses less digits than its factorization.

81263943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9029333 (or 9029330 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 81263943 is about 9014.6515739656. The cubic root of 81263943 is about 433.1443265803.

The spelling of 81263943 in words is "eighty-one million, two hundred sixty-three thousand, nine hundred forty-three".