21553246 has 72 divisors (see below), whose sum is σ = 42057792. Its totient is φ = 8236800.

The previous prime is 21553243. The next prime is 21553247. The reversal of 21553246 is 64235512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21553243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 695251 + ... + 695281.

It is an arithmetic number, because the mean of its divisors is an integer number (584136).

Almost surely, 2^21553246 is an apocalyptic number.

21553246 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21553246 is a deficient number, since it is larger than the sum of its proper divisors (20504546).

21553246 is a wasteful number, since it uses less digits than its factorization.

21553246 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98 (or 74 counting only the distinct ones).

The product of its digits is 7200, while the sum is 28.

The square root of 21553246 is about 4642.5473610939. The cubic root of 21553246 is about 278.2942470442.

Adding to 21553246 its reverse (64235512), we get a palindrome (85788758).

The spelling of 21553246 in words is "twenty-one million, five hundred fifty-three thousand, two hundred forty-six".