21554016 has 48 divisors (see below), whose sum is σ = 61725888. Its totient is φ = 6531200.

The previous prime is 21553997. The next prime is 21554033. The reversal of 21554016 is 61045512.

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

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

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, 9150 + ... + 11261.

It is an arithmetic number, because the mean of its divisors is an integer number (1285956).

Almost surely, 2^21554016 is an apocalyptic number.

It is an amenable number.

21554016 is an abundant number, since it is smaller than the sum of its proper divisors (40171872).

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

21554016 is a wasteful number, since it uses less digits than its factorization.

21554016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20435 (or 20427 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 21554016 is about 4642.6302889634. The cubic root of 21554016 is about 278.2975610697.

Adding to 21554016 its reverse (61045512), we get a palindrome (82599528).

The spelling of 21554016 in words is "twenty-one million, five hundred fifty-four thousand, sixteen".