21545908284 has 12 divisors (see below), whose sum is σ = 50273786024. Its totient is φ = 7181969424.

The previous prime is 21545908261. The next prime is 21545908289. The reversal of 21545908284 is 48280954512.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21545908289) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 897746167 + ... + 897746190.

Almost surely, 2^21545908284 is an apocalyptic number.

It is an amenable number.

21545908284 is an abundant number, since it is smaller than the sum of its proper divisors (28727877740).

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

21545908284 is a wasteful number, since it uses less digits than its factorization.

21545908284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1795492364 (or 1795492362 counting only the distinct ones).

The product of its (nonzero) digits is 921600, while the sum is 48.

The spelling of 21545908284 in words is "twenty-one billion, five hundred forty-five million, nine hundred eight thousand, two hundred eighty-four".