21516404322 has 32 divisors (see below), whose sum is σ = 49452084864. Its totient is φ = 6113577600.

The previous prime is 21516404303. The next prime is 21516404323. The reversal of 21516404322 is 22340461512.

It is a self number, because there is not a number n which added to its sum of digits gives 21516404322.

It is not an unprimeable number, because it can be changed into a prime (21516404323) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1407579 + ... + 1422782.

It is an arithmetic number, because the mean of its divisors is an integer number (1545377652).

Almost surely, 2^21516404322 is an apocalyptic number.

21516404322 is an abundant number, since it is smaller than the sum of its proper divisors (27935680542).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21516404322 is a wasteful number, since it uses less digits than its factorization.

21516404322 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2830554.

The product of its (nonzero) digits is 11520, while the sum is 30.

Adding to 21516404322 its reverse (22340461512), we get a palindrome (43856865834).

The spelling of 21516404322 in words is "twenty-one billion, five hundred sixteen million, four hundred four thousand, three hundred twenty-two".