1021120813 has 2 divisors, whose sum is σ = 1021120814. Its totient is φ = 1021120812.

The previous prime is 1021120799. The next prime is 1021120817. The reversal of 1021120813 is 3180211201.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 714065284 + 307055529 = 26722^2 + 17523^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1021120813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021120817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510560406 + 510560407.

It is an arithmetic number, because the mean of its divisors is an integer number (510560407).

Almost surely, 2^1021120813 is an apocalyptic number.

It is an amenable number.

1021120813 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021120813 is an equidigital number, since it uses as much as digits as its factorization.

1021120813 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 19.

The square root of 1021120813 is about 31954.9810358260. The cubic root of 1021120813 is about 1006.9912791099.

The spelling of 1021120813 in words is "one billion, twenty-one million, one hundred twenty thousand, eight hundred thirteen".