21899891616 has 48 divisors (see below), whose sum is σ = 57745062144. Its totient is φ = 7267221504.

The previous prime is 21899891597. The next prime is 21899891647. The reversal of 21899891616 is 61619899812.

It is a tau number, because it is divible by the number of its divisors (48).

It is a self number, because there is not a number n which added to its sum of digits gives 21899891616.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 490081 + ... + 532896.

It is an arithmetic number, because the mean of its divisors is an integer number (1203022128).

Almost surely, 2^21899891616 is an apocalyptic number.

It is an amenable number.

21899891616 is an abundant number, since it is smaller than the sum of its proper divisors (35845170528).

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

21899891616 is a wasteful number, since it uses less digits than its factorization.

21899891616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1023213 (or 1023205 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 60.

The spelling of 21899891616 in words is "twenty-one billion, eight hundred ninety-nine million, eight hundred ninety-one thousand, six hundred sixteen".