19767552221 has 2 divisors, whose sum is σ = 19767552222. Its totient is φ = 19767552220.

The previous prime is 19767552209. The next prime is 19767552263. The reversal of 19767552221 is 12225576791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19736035225 + 31516996 = 140485^2 + 5614^2 .

It is a cyclic number.

It is not a de Polignac number, because 19767552221 - 2³⁰ = 18693810397 is a prime.

It is a super-2 number, since 2×19767552221² (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 (19767552121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9883776110 + 9883776111.

It is an arithmetic number, because the mean of its divisors is an integer number (9883776111).

Almost surely, 2^19767552221 is an apocalyptic number.

It is an amenable number.

19767552221 is a deficient number, since it is larger than the sum of its proper divisors (1).

19767552221 is an equidigital number, since it uses as much as digits as its factorization.

19767552221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 529200, while the sum is 47.

The spelling of 19767552221 in words is "nineteen billion, seven hundred sixty-seven million, five hundred fifty-two thousand, two hundred twenty-one".