21325555 has 8 divisors (see below), whose sum is σ = 25648272. Its totient is φ = 17022048.

The previous prime is 21325553. The next prime is 21325567. The reversal of 21325555 is 55552312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21325555 - 2¹ = 21325553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21325553) 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, 2232 + ... + 6901.

It is an arithmetic number, because the mean of its divisors is an integer number (3206034).

Almost surely, 2^21325555 is an apocalyptic number.

21325555 is a deficient number, since it is larger than the sum of its proper divisors (4322717).

21325555 is an equidigital number, since it uses as much as digits as its factorization.

21325555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9605.

The product of its digits is 7500, while the sum is 28.

The square root of 21325555 is about 4617.9600474668. The cubic root of 21325555 is about 277.3107981733.

Adding to 21325555 its reverse (55552312), we get a palindrome (76877867).

The spelling of 21325555 in words is "twenty-one million, three hundred twenty-five thousand, five hundred fifty-five".