21034145 has 32 divisors (see below), whose sum is σ = 28753920. Its totient is φ = 14639040.

The previous prime is 21034133. The next prime is 21034183. The reversal of 21034145 is 54143012.

It is not a de Polignac number, because 21034145 - 2⁴ = 21034129 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 204164 + ... + 204266.

It is an arithmetic number, because the mean of its divisors is an integer number (898560).

Almost surely, 2^21034145 is an apocalyptic number.

It is an amenable number.

21034145 is a deficient number, since it is larger than the sum of its proper divisors (7719775).

21034145 is a wasteful number, since it uses less digits than its factorization.

21034145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 21034145 is about 4586.2997067353. The cubic root of 21034145 is about 276.0418659798.

Adding to 21034145 its reverse (54143012), we get a palindrome (75177157).

The spelling of 21034145 in words is "twenty-one million, thirty-four thousand, one hundred forty-five".