91388121 has 8 divisors (see below), whose sum is σ = 132928224. Its totient is φ = 55386720.

The previous prime is 91388083. The next prime is 91388123. The reversal of 91388121 is 12188319.

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

It is not a de Polignac number, because 91388121 - 2⁹ = 91387609 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 2769337 = 91388121 / (9 + 1 + 3 + 8 + 8 + 1 + 2 + 1).

It is not an unprimeable number, because it can be changed into a prime (91388123) 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, 1384636 + ... + 1384701.

It is an arithmetic number, because the mean of its divisors is an integer number (16616028).

Almost surely, 2^91388121 is an apocalyptic number.

It is an amenable number.

91388121 is a deficient number, since it is larger than the sum of its proper divisors (41540103).

91388121 is a wasteful number, since it uses less digits than its factorization.

91388121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2769351.

The product of its digits is 3456, while the sum is 33.

The square root of 91388121 is about 9559.7134371277. The cubic root of 91388121 is about 450.4327047800.

The spelling of 91388121 in words is "ninety-one million, three hundred eighty-eight thousand, one hundred twenty-one".