1021123189 has 2 divisors, whose sum is σ = 1021123190. Its totient is φ = 1021123188.

The previous prime is 1021123127. The next prime is 1021123211. The reversal of 1021123189 is 9813211201.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 937400689 + 83722500 = 30617^2 + 9150^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021123189 - 2¹⁷ = 1020992117 is a prime.

It is a super-2 number, since 2×1021123189² = 2085385134227059442, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021123109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510561594 + 510561595.

It is an arithmetic number, because the mean of its divisors is an integer number (510561595).

Almost surely, 2^1021123189 is an apocalyptic number.

It is an amenable number.

1021123189 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021123189 is an equidigital number, since it uses as much as digits as its factorization.

1021123189 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 1021123189 is about 31955.0182131070. The cubic root of 1021123189 is about 1006.9920601501.

The spelling of 1021123189 in words is "one billion, twenty-one million, one hundred twenty-three thousand, one hundred eighty-nine".