81743400 has 72 divisors (see below), whose sum is σ = 274527630. Its totient is φ = 21797760.

The previous prime is 81743383. The next prime is 81743407. The reversal of 81743400 is 434718.

It can be written as a sum of positive squares in 3 ways, for example, as 33385284 + 48358116 = 5778^2 + 6954^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (81743407) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 20907 + ... + 24506.

Almost surely, 2^81743400 is an apocalyptic number.

It is an amenable number.

81743400 is an abundant number, since it is smaller than the sum of its proper divisors (192784230).

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

81743400 is a wasteful number, since it uses less digits than its factorization.

81743400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45435 (or 45423 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 81743400 is about 9041.2056718117. The cubic root of 81743400 is about 433.9945067863.

The spelling of 81743400 in words is "eighty-one million, seven hundred forty-three thousand, four hundred".