91028397 has 8 divisors (see below), whose sum is σ = 121541056. Its totient is φ = 60600672.

The previous prime is 91028383. The next prime is 91028423. The reversal of 91028397 is 79382019.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91028397 - 2⁸ = 91028141 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91028317) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18688 + ... + 23049.

It is an arithmetic number, because the mean of its divisors is an integer number (15192632).

Almost surely, 2^91028397 is an apocalyptic number.

It is an amenable number.

91028397 is a deficient number, since it is larger than the sum of its proper divisors (30512659).

91028397 is a wasteful number, since it uses less digits than its factorization.

91028397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42467.

The product of its (nonzero) digits is 27216, while the sum is 39.

The square root of 91028397 is about 9540.8803052968. The cubic root of 91028397 is about 449.8409264907.

The spelling of 91028397 in words is "ninety-one million, twenty-eight thousand, three hundred ninety-seven".