19990221599 has 4 divisors (see below), whose sum is σ = 19992613464. Its totient is φ = 19987829736.

The previous prime is 19990221593. The next prime is 19990221631. The reversal of 19990221599 is 99512209991.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99512209991 = 89 ⋅1118114719.

It is a cyclic number.

It is not a de Polignac number, because 19990221599 - 2¹² = 19990217503 is a prime.

It is a super-2 number, since 2×19990221599² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19990221593) 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 3 ways as a sum of consecutive naturals, for example, 1183352 + ... + 1200125.

It is an arithmetic number, because the mean of its divisors is an integer number (4998153366).

Almost surely, 2^19990221599 is an apocalyptic number.

19990221599 is a deficient number, since it is larger than the sum of its proper divisors (2391865).

19990221599 is an equidigital number, since it uses as much as digits as its factorization.

19990221599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2391864.

The product of its (nonzero) digits is 1180980, while the sum is 56.

The spelling of 19990221599 in words is "nineteen billion, nine hundred ninety million, two hundred twenty-one thousand, five hundred ninety-nine".