91738728 has 24 divisors (see below), whose sum is σ = 248459250. Its totient is φ = 30579552.

The previous prime is 91738727. The next prime is 91738729. The reversal of 91738728 is 82783719.

It is an interprime number because it is at equal distance from previous prime (91738727) and next prime (91738729).

It can be written as a sum of positive squares in only one way, i.e., 82846404 + 8892324 = 9102^2 + 2982^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-3 number, since 3×91738728³ (a number of 25 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (91738723) 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, 637003 + ... + 637146.

Almost surely, 2^91738728 is an apocalyptic number.

It is an amenable number.

91738728 is an abundant number, since it is smaller than the sum of its proper divisors (156720522).

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

91738728 is a wasteful number, since it uses less digits than its factorization.

91738728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1274161 (or 1274154 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 91738728 is about 9578.0336186505. The cubic root of 91738728 is about 451.0079922806.

The spelling of 91738728 in words is "ninety-one million, seven hundred thirty-eight thousand, seven hundred twenty-eight".