19920064221 has 6 divisors (see below), whose sum is σ = 28773426110. Its totient is φ = 13280042808.

The previous prime is 19920064217. The next prime is 19920064223. The reversal of 19920064221 is 12246002991.

19920064221 is a `hidden beast` number, since 1 + 9 + 9 + 2 + 0 + 0 + 642 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 17151831225 + 2768232996 = 130965^2 + 52614^2 .

It is not a de Polignac number, because 19920064221 - 2² = 19920064217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19920064223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1106670226 + ... + 1106670243.

Almost surely, 2^19920064221 is an apocalyptic number.

It is an amenable number.

19920064221 is a deficient number, since it is larger than the sum of its proper divisors (8853361889).

19920064221 is a wasteful number, since it uses less digits than its factorization.

19920064221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2213340475 (or 2213340472 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The spelling of 19920064221 in words is "nineteen billion, nine hundred twenty million, sixty-four thousand, two hundred twenty-one".