81200393940 has 24 divisors (see below), whose sum is σ = 227361103200. Its totient is φ = 21653438368.

The previous prime is 81200393881. The next prime is 81200394013. The reversal of 81200393940 is 4939300218.

It is a super-2 number, since 2×81200393940² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 676669890 + ... + 676670009.

It is an arithmetic number, because the mean of its divisors is an integer number (9473379300).

Almost surely, 2^81200393940 is an apocalyptic number.

It is an amenable number.

81200393940 is an abundant number, since it is smaller than the sum of its proper divisors (146160709260).

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

81200393940 is a wasteful number, since it uses less digits than its factorization.

81200393940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1353339911 (or 1353339909 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 39.

The spelling of 81200393940 in words is "eighty-one billion, two hundred million, three hundred ninety-three thousand, nine hundred forty".