21065045 has 8 divisors (see below), whose sum is σ = 25524096. Its totient is φ = 16688016.

The previous prime is 21065041. The next prime is 21065059. The reversal of 21065045 is 54056012.

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 21065045 - 2² = 21065041 is a prime.

It is a super-2 number, since 2×21065045² = 887472241704050, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21065045.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21065041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19937 + ... + 20966.

It is an arithmetic number, because the mean of its divisors is an integer number (3190512).

Almost surely, 2^21065045 is an apocalyptic number.

It is an amenable number.

21065045 is a deficient number, since it is larger than the sum of its proper divisors (4459051).

21065045 is a wasteful number, since it uses less digits than its factorization.

21065045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41011.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 21065045 is about 4589.6671992640. The cubic root of 21065045 is about 276.1769720220.

The spelling of 21065045 in words is "twenty-one million, sixty-five thousand, forty-five".