19906572461 has 2 divisors, whose sum is σ = 19906572462. Its totient is φ = 19906572460.

The previous prime is 19906572397. The next prime is 19906572481. The reversal of 19906572461 is 16427560991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16681014025 + 3225558436 = 129155^2 + 56794^2 .

It is a cyclic number.

It is not a de Polignac number, because 19906572461 - 2⁶ = 19906572397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19906572481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9953286230 + 9953286231.

It is an arithmetic number, because the mean of its divisors is an integer number (9953286231).

Almost surely, 2^19906572461 is an apocalyptic number.

It is an amenable number.

19906572461 is a deficient number, since it is larger than the sum of its proper divisors (1).

19906572461 is an equidigital number, since it uses as much as digits as its factorization.

19906572461 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 816480, while the sum is 50.

The spelling of 19906572461 in words is "nineteen billion, nine hundred six million, five hundred seventy-two thousand, four hundred sixty-one".