193681728 has 42 divisors (see below), whose sum is σ = 555155354. Its totient is φ = 64560384.

The previous prime is 193681723. The next prime is 193681729. The reversal of 193681728 is 827186391.

It can be written as a sum of positive squares in only one way, i.e., 118200384 + 75481344 = 10872^2 + 8688^2 .

It is a super-2 number, since 2×193681728² = 75025223522131968, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (193681723) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 167551 + ... + 168702.

Almost surely, 2^193681728 is an apocalyptic number.

193681728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

193681728 is an abundant number, since it is smaller than the sum of its proper divisors (361473626).

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

193681728 is a wasteful number, since it uses less digits than its factorization.

193681728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336271 (or 336258 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 193681728 is about 13916.9582883617. The cubic root of 193681728 is about 578.5792893569.

The spelling of 193681728 in words is "one hundred ninety-three million, six hundred eighty-one thousand, seven hundred twenty-eight".