19984295821 has 64 divisors (see below), whose sum is σ = 26469504000. Its totient is φ = 14680866816.

The previous prime is 19984295813. The next prime is 19984295833. The reversal of 19984295821 is 12859248991.

It is not a de Polignac number, because 19984295821 - 2³ = 19984295813 is a prime.

It is a super-2 number, since 2×19984295821² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19984295621) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5792505 + ... + 5795953.

It is an arithmetic number, because the mean of its divisors is an integer number (413586000).

Almost surely, 2^19984295821 is an apocalyptic number.

It is an amenable number.

19984295821 is a deficient number, since it is larger than the sum of its proper divisors (6485208179).

19984295821 is a wasteful number, since it uses less digits than its factorization.

19984295821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3598.

The product of its digits is 3732480, while the sum is 58.

The spelling of 19984295821 in words is "nineteen billion, nine hundred eighty-four million, two hundred ninety-five thousand, eight hundred twenty-one".