21554450 has 24 divisors (see below), whose sum is σ = 41836608. Its totient is φ = 8246480.

The previous prime is 21554443. The next prime is 21554459. The reversal of 21554450 is 5445512.

It is not an unprimeable number, because it can be changed into a prime (21554459) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8222 + ... + 10521.

It is an arithmetic number, because the mean of its divisors is an integer number (1743192).

Almost surely, 2^21554450 is an apocalyptic number.

21554450 is a deficient number, since it is larger than the sum of its proper divisors (20282158).

21554450 is a wasteful number, since it uses less digits than its factorization.

21554450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18778 (or 18773 counting only the distinct ones).

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

The square root of 21554450 is about 4642.6770294734. The cubic root of 21554450 is about 278.2994289402.

Adding to 21554450 its reverse (5445512), we get a palindrome (26999962).

The spelling of 21554450 in words is "twenty-one million, five hundred fifty-four thousand, four hundred fifty".