91024021 has 4 divisors (see below), whose sum is σ = 99298944. Its totient is φ = 82749100.

The previous prime is 91024019. The next prime is 91024027. The reversal of 91024021 is 12042019.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 91024021 - 2¹ = 91024019 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91024021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91024027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4137445 + ... + 4137466.

It is an arithmetic number, because the mean of its divisors is an integer number (24824736).

Almost surely, 2^91024021 is an apocalyptic number.

It is an amenable number.

91024021 is a deficient number, since it is larger than the sum of its proper divisors (8274923).

91024021 is a wasteful number, since it uses less digits than its factorization.

91024021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8274922.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 91024021 is about 9540.6509735971. The cubic root of 91024021 is about 449.8337179876.

The spelling of 91024021 in words is "ninety-one million, twenty-four thousand, twenty-one".