21554124 has 12 divisors (see below), whose sum is σ = 50292984. Its totient is φ = 7184704.

The previous prime is 21554111. The next prime is 21554149. The reversal of 21554124 is 42145512.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21554124² = 929160522814752, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21554094 and 21554103.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 898077 + ... + 898100.

It is an arithmetic number, because the mean of its divisors is an integer number (4191082).

Almost surely, 2^21554124 is an apocalyptic number.

It is an amenable number.

21554124 is an abundant number, since it is smaller than the sum of its proper divisors (28738860).

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

21554124 is a wasteful number, since it uses less digits than its factorization.

21554124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1796184 (or 1796182 counting only the distinct ones).

The product of its digits is 1600, while the sum is 24.

The square root of 21554124 is about 4642.6419202863. The cubic root of 21554124 is about 278.2980258877.

Adding to 21554124 its reverse (42145512), we get a palindrome (63699636).

The spelling of 21554124 in words is "twenty-one million, five hundred fifty-four thousand, one hundred twenty-four".