2158923509 has 2 divisors, whose sum is σ = 2158923510. Its totient is φ = 2158923508.

The previous prime is 2158923499. The next prime is 2158923553. The reversal of 2158923509 is 9053298512.

2158923509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (2158923553) can be obtained adding 2158923509 to its sum of digits (44).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2150640625 + 8282884 = 46375^2 + 2878^2 .

It is a cyclic number.

It is not a de Polignac number, because 2158923509 - 2⁴ = 2158923493 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2158923509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2158923409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1079461754 + 1079461755.

It is an arithmetic number, because the mean of its divisors is an integer number (1079461755).

Almost surely, 2^2158923509 is an apocalyptic number.

It is an amenable number.

2158923509 is a deficient number, since it is larger than the sum of its proper divisors (1).

2158923509 is an equidigital number, since it uses as much as digits as its factorization.

2158923509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 194400, while the sum is 44.

The square root of 2158923509 is about 46464.2175119737. The cubic root of 2158923509 is about 1292.4460348577.

The spelling of 2158923509 in words is "two billion, one hundred fifty-eight million, nine hundred twenty-three thousand, five hundred nine".