21442550 has 12 divisors (see below), whose sum is σ = 39883236. Its totient is φ = 8577000.

The previous prime is 21442543. The next prime is 21442591. The reversal of 21442550 is 5524412.

It is a happy number.

It is a plaindrome in base 13.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 214376 + ... + 214475.

It is an arithmetic number, because the mean of its divisors is an integer number (3323603).

Almost surely, 2^21442550 is an apocalyptic number.

21442550 is a deficient number, since it is larger than the sum of its proper divisors (18440686).

21442550 is a wasteful number, since it uses less digits than its factorization.

21442550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428863 (or 428858 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 21442550 is about 4630.6101109897. The cubic root of 21442550 is about 277.8169956480.

Adding to 21442550 its reverse (5524412), we get a palindrome (26966962).

The spelling of 21442550 in words is "twenty-one million, four hundred forty-two thousand, five hundred fifty".