19741162561 has 2 divisors, whose sum is σ = 19741162562. Its totient is φ = 19741162560.

The previous prime is 19741162541. The next prime is 19741162579. The reversal of 19741162561 is 16526114791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19111403536 + 629759025 = 138244^2 + 25095^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19741162561 is a prime.

It is not a weakly prime, because it can be changed into another prime (19741162531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9870581280 + 9870581281.

It is an arithmetic number, because the mean of its divisors is an integer number (9870581281).

Almost surely, 2^19741162561 is an apocalyptic number.

It is an amenable number.

19741162561 is a deficient number, since it is larger than the sum of its proper divisors (1).

19741162561 is an equidigital number, since it uses as much as digits as its factorization.

19741162561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 43.

The spelling of 19741162561 in words is "nineteen billion, seven hundred forty-one million, one hundred sixty-two thousand, five hundred sixty-one".