9091021 has 2 divisors, whose sum is σ = 9091022. Its totient is φ = 9091020.

The previous prime is 9091009. The next prime is 9091051. The reversal of 9091021 is 1201909.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4888521 + 4202500 = 2211^2 + 2050^2 .

It is an emirp because it is prime and its reverse (1201909) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9091021 - 2⁵ = 9090989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 9090983 and 9091001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9091051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4545510 + 4545511.

It is an arithmetic number, because the mean of its divisors is an integer number (4545511).

Almost surely, 2^9091021 is an apocalyptic number.

It is an amenable number.

9091021 is a deficient number, since it is larger than the sum of its proper divisors (1).

9091021 is an equidigital number, since it uses as much as digits as its factorization.

9091021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 9091021 is about 3015.1320037438. The cubic root of 9091021 is about 208.7072586307.

The spelling of 9091021 in words is "nine million, ninety-one thousand, twenty-one".