19903162661 has 2 divisors, whose sum is σ = 19903162662. Its totient is φ = 19903162660.

The previous prime is 19903162619. The next prime is 19903162673. The reversal of 19903162661 is 16626130991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13068833761 + 6834328900 = 114319^2 + 82670^2 .

It is a cyclic number.

It is not a de Polignac number, because 19903162661 - 2⁶ = 19903162597 is a prime.

It is a super-2 number, since 2×19903162661² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19903162561) 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, 9951581330 + 9951581331.

It is an arithmetic number, because the mean of its divisors is an integer number (9951581331).

Almost surely, 2^19903162661 is an apocalyptic number.

It is an amenable number.

19903162661 is a deficient number, since it is larger than the sum of its proper divisors (1).

19903162661 is an equidigital number, since it uses as much as digits as its factorization.

19903162661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 104976, while the sum is 44.

The spelling of 19903162661 in words is "nineteen billion, nine hundred three million, one hundred sixty-two thousand, six hundred sixty-one".