81007700 has 36 divisors (see below), whose sum is σ = 179884320. Its totient is φ = 31647840.

The previous prime is 81007699. The next prime is 81007727. The reversal of 81007700 is 770018.

It is a congruent number.

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, 5120 + ... + 13719.

Almost surely, 2^81007700 is an apocalyptic number.

It is an amenable number.

81007700 is an abundant number, since it is smaller than the sum of its proper divisors (98876620).

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

81007700 is a wasteful number, since it uses less digits than its factorization.

81007700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18896 (or 18889 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 23.

The square root of 81007700 is about 9000.4277676119. The cubic root of 81007700 is about 432.6885809315.

Adding to 81007700 its reverse (770018), we get a palindrome (81777718).

The spelling of 81007700 in words is "eighty-one million, seven thousand, seven hundred".