21026454 has 16 divisors (see below), whose sum is σ = 42115248. Its totient is φ = 6998432.

The previous prime is 21026443. The next prime is 21026477. The reversal of 21026454 is 45462012.

It is a super-2 number, since 2×21026454² = 884223535628232, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2584 + ... + 6980.

It is an arithmetic number, because the mean of its divisors is an integer number (2632203).

Almost surely, 2^21026454 is an apocalyptic number.

21026454 is an abundant number, since it is smaller than the sum of its proper divisors (21088794).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21026454 is a wasteful number, since it uses less digits than its factorization.

21026454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5199.

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 21026454 is about 4585.4611545623. The cubic root of 21026454 is about 276.0082175667.

Adding to 21026454 its reverse (45462012), we get a palindrome (66488466).

The spelling of 21026454 in words is "twenty-one million, twenty-six thousand, four hundred fifty-four".