21261454 has 8 divisors (see below), whose sum is σ = 31989528. Its totient is φ = 10598280.

The previous prime is 21261433. The next prime is 21261463. The reversal of 21261454 is 45416212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

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 3 ways as a sum of consecutive naturals, for example, 15397 + ... + 16720.

It is an arithmetic number, because the mean of its divisors is an integer number (3998691).

Almost surely, 2^21261454 is an apocalyptic number.

21261454 is a deficient number, since it is larger than the sum of its proper divisors (10728074).

21261454 is a wasteful number, since it uses less digits than its factorization.

21261454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32450.

The product of its digits is 1920, while the sum is 25.

The square root of 21261454 is about 4611.0144220117. The cubic root of 21261454 is about 277.0326695819.

Adding to 21261454 its reverse (45416212), we get a palindrome (66677666).

The spelling of 21261454 in words is "twenty-one million, two hundred sixty-one thousand, four hundred fifty-four".