21341555 has 4 divisors (see below), whose sum is σ = 25609872. Its totient is φ = 17073240.

The previous prime is 21341549. The next prime is 21341557. The reversal of 21341555 is 55514312.

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

It is not a de Polignac number, because 21341555 - 2⁶ = 21341491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21341557) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 2134151 + ... + 2134160.

It is an arithmetic number, because the mean of its divisors is an integer number (6402468).

Almost surely, 2^21341555 is an apocalyptic number.

21341555 is a deficient number, since it is larger than the sum of its proper divisors (4268317).

21341555 is an equidigital number, since it uses as much as digits as its factorization.

21341555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4268316.

The product of its digits is 3000, while the sum is 26.

The square root of 21341555 is about 4619.6920893064. The cubic root of 21341555 is about 277.3801338222.

Adding to 21341555 its reverse (55514312), we get a palindrome (76855867).

The spelling of 21341555 in words is "twenty-one million, three hundred forty-one thousand, five hundred fifty-five".