21050407 has 16 divisors (see below), whose sum is σ = 24837120. Its totient is φ = 17467488.

The previous prime is 21050401. The next prime is 21050413. The reversal of 21050407 is 70405012.

It is an interprime number because it is at equal distance from previous prime (21050401) and next prime (21050413).

It is a cyclic number.

It is not a de Polignac number, because 21050407 - 2³ = 21050399 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21050401) 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, 35568 + ... + 36154.

It is an arithmetic number, because the mean of its divisors is an integer number (1552320).

Almost surely, 2^21050407 is an apocalyptic number.

21050407 is a deficient number, since it is larger than the sum of its proper divisors (3786713).

21050407 is a wasteful number, since it uses less digits than its factorization.

21050407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 750.

The product of its (nonzero) digits is 280, while the sum is 19.

The square root of 21050407 is about 4588.0722531364. The cubic root of 21050407 is about 276.1129858419.

Adding to 21050407 its reverse (70405012), we get a palindrome (91455419).

The spelling of 21050407 in words is "twenty-one million, fifty thousand, four hundred seven".