21550452 has 96 divisors (see below), whose sum is σ = 63673344. Its totient is φ = 5510400.

The previous prime is 21550447. The next prime is 21550453. The reversal of 21550452 is 25405512.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21550453) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 76552 + ... + 76832.

It is an arithmetic number, because the mean of its divisors is an integer number (663264).

Almost surely, 2^21550452 is an apocalyptic number.

21550452 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21550452, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31836672).

21550452 is an abundant number, since it is smaller than the sum of its proper divisors (42122892).

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

21550452 is a wasteful number, since it uses less digits than its factorization.

21550452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389 (or 387 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 24.

The square root of 21550452 is about 4642.2464389560. The cubic root of 21550452 is about 278.2822212032.

Adding to 21550452 its reverse (25405512), we get a palindrome (46955964).

The spelling of 21550452 in words is "twenty-one million, five hundred fifty thousand, four hundred fifty-two".