21040965 has 40 divisors (see below), whose sum is σ = 41155488. Its totient is φ = 10199520.

The previous prime is 21040963. The next prime is 21040967. The reversal of 21040965 is 56904012.

It is an interprime number because it is at equal distance from previous prime (21040963) and next prime (21040967).

It is not a de Polignac number, because 21040965 - 2¹ = 21040963 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21040963) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 2094 + ... + 6816.

Almost surely, 2^21040965 is an apocalyptic number.

It is an amenable number.

21040965 is a deficient number, since it is larger than the sum of its proper divisors (20114523).

21040965 is a wasteful number, since it uses less digits than its factorization.

21040965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4751 (or 4742 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 21040965 is about 4587.0431652645. The cubic root of 21040965 is about 276.0716968745.

Adding to 21040965 its reverse (56904012), we get a palindrome (77944977).

The spelling of 21040965 in words is "twenty-one million, forty thousand, nine hundred sixty-five".