21554252 has 24 divisors (see below), whose sum is σ = 38673936. Its totient is φ = 10507328.

The previous prime is 21554237. The next prime is 21554257. The reversal of 21554252 is 25245512.

It is not an unprimeable number, because it can be changed into a prime (21554257) 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, 61943 + ... + 62289.

It is an arithmetic number, because the mean of its divisors is an integer number (1611414).

Almost surely, 2^21554252 is an apocalyptic number.

It is an amenable number.

21554252 is a deficient number, since it is larger than the sum of its proper divisors (17119684).

21554252 is a wasteful number, since it uses less digits than its factorization.

21554252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 697 (or 695 counting only the distinct ones).

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

The square root of 21554252 is about 4642.6557055203. The cubic root of 21554252 is about 278.2985767812.

Adding to 21554252 its reverse (25245512), we get a palindrome (46799764).

The spelling of 21554252 in words is "twenty-one million, five hundred fifty-four thousand, two hundred fifty-two".