921113021 has 2 divisors, whose sum is σ = 921113022. Its totient is φ = 921113020.

The previous prime is 921113009. The next prime is 921113029. The reversal of 921113021 is 120311129.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 894847396 + 26265625 = 29914^2 + 5125^2 .

It is an emirp because it is prime and its reverse (120311129) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 921113021 - 2⁶ = 921112957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 921112984 and 921113002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (921113029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 460556510 + 460556511.

It is an arithmetic number, because the mean of its divisors is an integer number (460556511).

Almost surely, 2^921113021 is an apocalyptic number.

It is an amenable number.

921113021 is a deficient number, since it is larger than the sum of its proper divisors (1).

921113021 is an equidigital number, since it uses as much as digits as its factorization.

921113021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 921113021 is about 30349.8438381485. The cubic root of 921113021 is about 972.9808825733.

The spelling of 921113021 in words is "nine hundred twenty-one million, one hundred thirteen thousand, twenty-one".