20494251389 has 2 divisors, whose sum is σ = 20494251390. Its totient is φ = 20494251388.

The previous prime is 20494251341. The next prime is 20494251397. The reversal of 20494251389 is 98315249402.

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., 14401200025 + 6093051364 = 120005^2 + 78058^2 .

It is a cyclic number.

It is not a de Polignac number, because 20494251389 - 2⁸ = 20494251133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20494251319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10247125694 + 10247125695.

It is an arithmetic number, because the mean of its divisors is an integer number (10247125695).

Almost surely, 2^20494251389 is an apocalyptic number.

It is an amenable number.

20494251389 is a deficient number, since it is larger than the sum of its proper divisors (1).

20494251389 is an equidigital number, since it uses as much as digits as its factorization.

20494251389 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 20494251389 in words is "twenty billion, four hundred ninety-four million, two hundred fifty-one thousand, three hundred eighty-nine".