21267609888 has 48 divisors (see below), whose sum is σ = 63802831680. Its totient is φ = 6076459776.

The previous prime is 21267609823. The next prime is 21267609917. The reversal of 21267609888 is 88890676212.

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

It is a super-2 number, since 2×21267609888² (a number of 21 digits) contains 22 as substring.

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, 15823443 + ... + 15824786.

It is an arithmetic number, because the mean of its divisors is an integer number (1329225660).

Almost surely, 2^21267609888 is an apocalyptic number.

21267609888 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21267609888 is an abundant number, since it is smaller than the sum of its proper divisors (42535221792).

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

21267609888 is a wasteful number, since it uses less digits than its factorization.

21267609888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31648249 (or 31648241 counting only the distinct ones).

The product of its (nonzero) digits is 4644864, while the sum is 57.

The spelling of 21267609888 in words is "twenty-one billion, two hundred sixty-seven million, six hundred nine thousand, eight hundred eighty-eight".