28219344509 has 2 divisors, whose sum is σ = 28219344510. Its totient is φ = 28219344508.

The previous prime is 28219344481. The next prime is 28219344533. The reversal of 28219344509 is 90544391282.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26616943609 + 1602400900 = 163147^2 + 40030^2 .

It is a cyclic number.

It is not a de Polignac number, because 28219344509 - 2²⁸ = 27950909053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28219344709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14109672254 + 14109672255.

It is an arithmetic number, because the mean of its divisors is an integer number (14109672255).

Almost surely, 2^28219344509 is an apocalyptic number.

It is an amenable number.

28219344509 is a deficient number, since it is larger than the sum of its proper divisors (1).

28219344509 is an equidigital number, since it uses as much as digits as its factorization.

28219344509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 622080, while the sum is 47.

The spelling of 28219344509 in words is "twenty-eight billion, two hundred nineteen million, three hundred forty-four thousand, five hundred nine".