19666531033 has 2 divisors, whose sum is σ = 19666531034. Its totient is φ = 19666531032.

The previous prime is 19666531013. The next prime is 19666531061. The reversal of 19666531033 is 33013566691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18636891289 + 1029639744 = 136517^2 + 32088^2 .

It is a cyclic number.

It is not a de Polignac number, because 19666531033 - 2³³ = 11076596441 is a prime.

It is not a weakly prime, because it can be changed into another prime (19666531013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9833265516 + 9833265517.

It is an arithmetic number, because the mean of its divisors is an integer number (9833265517).

Almost surely, 2^19666531033 is an apocalyptic number.

It is an amenable number.

19666531033 is a deficient number, since it is larger than the sum of its proper divisors (1).

19666531033 is an equidigital number, since it uses as much as digits as its factorization.

19666531033 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 262440, while the sum is 43.

The spelling of 19666531033 in words is "nineteen billion, six hundred sixty-six million, five hundred thirty-one thousand, thirty-three".