21450554 has 16 divisors (see below), whose sum is σ = 32870400. Its totient is φ = 10496304.

The previous prime is 21450553. The next prime is 21450581. The reversal of 21450554 is 45505412.

It is not an unprimeable number, because it can be changed into a prime (21450553) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19532 + ... + 20600.

It is an arithmetic number, because the mean of its divisors is an integer number (2054400).

Almost surely, 2^21450554 is an apocalyptic number.

21450554 is a deficient number, since it is larger than the sum of its proper divisors (11419846).

21450554 is a wasteful number, since it uses less digits than its factorization.

21450554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1277.

The product of its (nonzero) digits is 4000, while the sum is 26.

The square root of 21450554 is about 4631.4742793197. The cubic root of 21450554 is about 277.8515588663.

Adding to 21450554 its reverse (45505412), we get a palindrome (66955966).

The spelling of 21450554 in words is "twenty-one million, four hundred fifty thousand, five hundred fifty-four".