19237864561 has 2 divisors, whose sum is σ = 19237864562. Its totient is φ = 19237864560.

The previous prime is 19237864537. The next prime is 19237864571. The reversal of 19237864561 is 16546873291.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18528654400 + 709210161 = 136120^2 + 26631^2 .

It is a cyclic number.

It is not a de Polignac number, because 19237864561 - 2⁷ = 19237864433 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19237864499 and 19237864508.

It is not a weakly prime, because it can be changed into another prime (19237864571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9618932280 + 9618932281.

It is an arithmetic number, because the mean of its divisors is an integer number (9618932281).

Almost surely, 2^19237864561 is an apocalyptic number.

It is an amenable number.

19237864561 is a deficient number, since it is larger than the sum of its proper divisors (1).

19237864561 is an equidigital number, since it uses as much as digits as its factorization.

19237864561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2177280, while the sum is 52.

The spelling of 19237864561 in words is "nineteen billion, two hundred thirty-seven million, eight hundred sixty-four thousand, five hundred sixty-one".