21655011448 has 16 divisors (see below), whose sum is σ = 46403596080. Its totient is φ = 9280719168.

The previous prime is 21655011439. The next prime is 21655011473. The reversal of 21655011448 is 84411055612.

It is a super-2 number, since 2×21655011448² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 193348261 + ... + 193348372.

It is an arithmetic number, because the mean of its divisors is an integer number (2900224755).

Almost surely, 2^21655011448 is an apocalyptic number.

21655011448 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21655011448 is an abundant number, since it is smaller than the sum of its proper divisors (24748584632).

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

21655011448 is a wasteful number, since it uses less digits than its factorization.

21655011448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386696646 (or 386696642 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 37.

The spelling of 21655011448 in words is "twenty-one billion, six hundred fifty-five million, eleven thousand, four hundred forty-eight".