81745700 has 18 divisors (see below), whose sum is σ = 177388386. Its totient is φ = 32698240.

The previous prime is 81745687. The next prime is 81745717. The reversal of 81745700 is 754718.

It can be written as a sum of positive squares in 3 ways, for example, as 19430464 + 62315236 = 4408^2 + 7894^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 408629 + ... + 408828.

Almost surely, 2^81745700 is an apocalyptic number.

It is an amenable number.

81745700 is an abundant number, since it is smaller than the sum of its proper divisors (95642686).

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

81745700 is a wasteful number, since it uses less digits than its factorization.

81745700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 817471 (or 817464 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 32.

The square root of 81745700 is about 9041.3328663422. The cubic root of 81745700 is about 433.9985771577.

The spelling of 81745700 in words is "eighty-one million, seven hundred forty-five thousand, seven hundred".