21027145 has 16 divisors (see below), whose sum is σ = 26191872. Its totient is φ = 16188480.

The previous prime is 21027143. The next prime is 21027169. The reversal of 21027145 is 54172012.

It is a happy number.

It is not a de Polignac number, because 21027145 - 2¹ = 21027143 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21027143) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45184 + ... + 45646.

It is an arithmetic number, because the mean of its divisors is an integer number (1636992).

Almost surely, 2^21027145 is an apocalyptic number.

It is an amenable number.

21027145 is a deficient number, since it is larger than the sum of its proper divisors (5164727).

21027145 is a wasteful number, since it uses less digits than its factorization.

21027145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 792.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21027145 is about 4585.5365007816. The cubic root of 21027145 is about 276.0112410531.

Adding to 21027145 its reverse (54172012), we get a palindrome (75199157).

The spelling of 21027145 in words is "twenty-one million, twenty-seven thousand, one hundred forty-five".