21413155 has 4 divisors (see below), whose sum is σ = 25695792. Its totient is φ = 17130520.

The previous prime is 21413143. The next prime is 21413167. The reversal of 21413155 is 55131412.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (21413143) and next prime (21413167).

It is not a de Polignac number, because 21413155 - 2⁵ = 21413123 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 2141311 + ... + 2141320.

It is an arithmetic number, because the mean of its divisors is an integer number (6423948).

Almost surely, 2^21413155 is an apocalyptic number.

21413155 is a deficient number, since it is larger than the sum of its proper divisors (4282637).

21413155 is an equidigital number, since it uses as much as digits as its factorization.

21413155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4282636.

The product of its digits is 600, while the sum is 22.

The square root of 21413155 is about 4627.4350346601. The cubic root of 21413155 is about 277.6899870421.

Adding to 21413155 its reverse (55131412), we get a palindrome (76544567).

The spelling of 21413155 in words is "twenty-one million, four hundred thirteen thousand, one hundred fifty-five".