21054451 has 16 divisors (see below), whose sum is σ = 24393600. Its totient is φ = 17971200.

The previous prime is 21054437. The next prime is 21054457. The reversal of 21054451 is 15445012.

It is a cyclic number.

It is not a de Polignac number, because 21054451 - 2⁵ = 21054419 is a prime.

It is a super-2 number, since 2×21054451² = 886579813822802, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21054457) 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, 26995 + ... + 27763.

It is an arithmetic number, because the mean of its divisors is an integer number (1524600).

Almost surely, 2^21054451 is an apocalyptic number.

21054451 is a deficient number, since it is larger than the sum of its proper divisors (3339149).

21054451 is a wasteful number, since it uses less digits than its factorization.

21054451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 930.

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

The square root of 21054451 is about 4588.5129399403. The cubic root of 21054451 is about 276.1306660926.

Adding to 21054451 its reverse (15445012), we get a palindrome (36499463).

It can be divided in two parts, 2105 and 4451, that added together give a palindrome (6556).

The spelling of 21054451 in words is "twenty-one million, fifty-four thousand, four hundred fifty-one".