21550054 has 4 divisors (see below), whose sum is σ = 32325084. Its totient is φ = 10775026.

The previous prime is 21550049. The next prime is 21550069. The reversal of 21550054 is 45005512.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5387512 + ... + 5387515.

It is an arithmetic number, because the mean of its divisors is an integer number (8081271).

Almost surely, 2^21550054 is an apocalyptic number.

21550054 is a deficient number, since it is larger than the sum of its proper divisors (10775030).

21550054 is a wasteful number, since it uses less digits than its factorization.

21550054 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10775029.

The product of its (nonzero) digits is 1000, while the sum is 22.

The square root of 21550054 is about 4642.2035715811. The cubic root of 21550054 is about 278.2805080604.

Adding to 21550054 its reverse (45005512), we get a palindrome (66555566).

The spelling of 21550054 in words is "twenty-one million, five hundred fifty thousand, fifty-four".