21151165 has 8 divisors (see below), whose sum is σ = 29007360. Its totient is φ = 14503632.

The previous prime is 21151159. The next prime is 21151171. The reversal of 21151165 is 56115112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21151159) and next prime (21151171).

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 21151165 - 2⁹ = 21150653 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 302125 + ... + 302194.

It is an arithmetic number, because the mean of its divisors is an integer number (3625920).

Almost surely, 2^21151165 is an apocalyptic number.

It is an amenable number.

21151165 is a deficient number, since it is larger than the sum of its proper divisors (7856195).

21151165 is an equidigital number, since it uses as much as digits as its factorization.

21151165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 604331.

The product of its digits is 300, while the sum is 22.

The square root of 21151165 is about 4599.0395736501. The cubic root of 21151165 is about 276.5528240840.

Adding to 21151165 its reverse (56115112), we get a palindrome (77266277).

It can be divided in two parts, 21151 and 165, that added together give a square (21316 = 146²).

The spelling of 21151165 in words is "twenty-one million, one hundred fifty-one thousand, one hundred sixty-five".