1123421021 has 2 divisors, whose sum is σ = 1123421022. Its totient is φ = 1123421020.

The previous prime is 1123421003. The next prime is 1123421029. The reversal of 1123421021 is 1201243211.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1075118521 + 48302500 = 32789^2 + 6950^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1123421021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1123421029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 561710510 + 561710511.

It is an arithmetic number, because the mean of its divisors is an integer number (561710511).

Almost surely, 2^1123421021 is an apocalyptic number.

It is an amenable number.

1123421021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1123421021 is an equidigital number, since it uses as much as digits as its factorization.

1123421021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 1123421021 is about 33517.4733683791. The cubic root of 1123421021 is about 1039.5551046415. Note that the first 3 decimals are identical.

Adding to 1123421021 its reverse (1201243211), we get a palindrome (2324664232).

The spelling of 1123421021 in words is "one billion, one hundred twenty-three million, four hundred twenty-one thousand, twenty-one".