21054415 has 16 divisors (see below), whose sum is σ = 27158112. Its totient is φ = 15611904.

The previous prime is 21054403. The next prime is 21054419. The reversal of 21054415 is 51445012.

It is a cyclic number.

It is not a de Polignac number, because 21054415 - 2⁷ = 21054287 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21054419) 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, 3847 + ... + 7543.

It is an arithmetic number, because the mean of its divisors is an integer number (1697382).

Almost surely, 2^21054415 is an apocalyptic number.

21054415 is a deficient number, since it is larger than the sum of its proper divisors (6103697).

21054415 is a wasteful number, since it uses less digits than its factorization.

21054415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3786.

The product of its (nonzero) digits is 800, while the sum is 22.

The square root of 21054415 is about 4588.5090170991. The cubic root of 21054415 is about 276.1305087116.

Adding to 21054415 its reverse (51445012), we get a palindrome (72499427).

The spelling of 21054415 in words is "twenty-one million, fifty-four thousand, four hundred fifteen".