81643302 has 40 divisors (see below), whose sum is σ = 197018976. Its totient is φ = 25120368.

The previous prime is 81643279. The next prime is 81643327. The reversal of 81643302 is 20334618.

It is a happy number.

It is a super-2 number, since 2×81643302² = 13331257522926408, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 17278 + ... + 21489.

Almost surely, 2^81643302 is an apocalyptic number.

81643302 is an abundant number, since it is smaller than the sum of its proper divisors (115375674).

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

81643302 is a wasteful number, since it uses less digits than its factorization.

81643302 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38794 (or 38785 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 81643302 is about 9035.6683206058. The cubic root of 81643302 is about 433.8172866627.

The spelling of 81643302 in words is "eighty-one million, six hundred forty-three thousand, three hundred two".