21011045 has 12 divisors (see below), whose sum is σ = 27714540. Its totient is φ = 15280320.

The previous prime is 21011033. The next prime is 21011063. The reversal of 21011045 is 54011012.

It can be written as a sum of positive squares in 2 ways, for example, as 2982529 + 18028516 = 1727^2 + 4246^2 .

It is not a de Polignac number, because 21011045 - 2¹⁸ = 20748901 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16760 + ... + 17969.

It is an arithmetic number, because the mean of its divisors is an integer number (2309545).

Almost surely, 2^21011045 is an apocalyptic number.

It is an amenable number.

21011045 is a deficient number, since it is larger than the sum of its proper divisors (6703495).

21011045 is a wasteful number, since it uses less digits than its factorization.

21011045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34756 (or 34745 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 21011045 is about 4583.7806448389. The cubic root of 21011045 is about 275.9407779187.

Adding to 21011045 its reverse (54011012), we get a palindrome (75022057).

The spelling of 21011045 in words is "twenty-one million, eleven thousand, forty-five".