19061561 has 2 divisors, whose sum is σ = 19061562. Its totient is φ = 19061560.

The previous prime is 19061551. The next prime is 19061563. The reversal of 19061561 is 16516091.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14137600 + 4923961 = 3760^2 + 2219^2 .

It is a cyclic number.

It is not a de Polignac number, because 19061561 - 2²² = 14867257 is a prime.

Together with 19061563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19061563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9530780 + 9530781.

It is an arithmetic number, because the mean of its divisors is an integer number (9530781).

Almost surely, 2^19061561 is an apocalyptic number.

It is an amenable number.

19061561 is a deficient number, since it is larger than the sum of its proper divisors (1).

19061561 is an equidigital number, since it uses as much as digits as its factorization.

19061561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 19061561 is about 4365.9547638518. The cubic root of 19061561 is about 267.1280462382.

The spelling of 19061561 in words is "nineteen million, sixty-one thousand, five hundred sixty-one".