1021240109 has 2 divisors, whose sum is σ = 1021240110. Its totient is φ = 1021240108.

The previous prime is 1021240091. The next prime is 1021240127. The reversal of 1021240109 is 9010421201.

Together with previous prime (1021240091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a balanced prime because it is at equal distance from previous prime (1021240091) and next prime (1021240127).

It can be written as a sum of positive squares in only one way, i.e., 716632900 + 304607209 = 26770^2 + 17453^2 .

It is an emirp because it is prime and its reverse (9010421201) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1021240109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021240169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510620054 + 510620055.

It is an arithmetic number, because the mean of its divisors is an integer number (510620055).

Almost surely, 2^1021240109 is an apocalyptic number.

It is an amenable number.

1021240109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021240109 is an equidigital number, since it uses as much as digits as its factorization.

1021240109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 1021240109 is about 31956.8476073595. The cubic root of 1021240109 is about 1007.0304926721.

The spelling of 1021240109 in words is "one billion, twenty-one million, two hundred forty thousand, one hundred nine".