19528261397 has 2 divisors, whose sum is σ = 19528261398. Its totient is φ = 19528261396.

The previous prime is 19528261283. The next prime is 19528261447. The reversal of 19528261397 is 79316282591.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16537702801 + 2990558596 = 128599^2 + 54686^2 .

It is a cyclic number.

It is not a de Polignac number, because 19528261397 - 2²⁶ = 19461152533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19528264397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9764130698 + 9764130699.

It is an arithmetic number, because the mean of its divisors is an integer number (9764130699).

Almost surely, 2^19528261397 is an apocalyptic number.

It is an amenable number.

19528261397 is a deficient number, since it is larger than the sum of its proper divisors (1).

19528261397 is an equidigital number, since it uses as much as digits as its factorization.

19528261397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1632960, while the sum is 53.

The spelling of 19528261397 in words is "nineteen billion, five hundred twenty-eight million, two hundred sixty-one thousand, three hundred ninety-seven".