21121454 has 16 divisors (see below), whose sum is σ = 33397920. Its totient is φ = 10002720.

The previous prime is 21121453. The next prime is 21121493. The reversal of 21121454 is 45412112.

It is a happy number.

It is a super-2 number, since 2×21121454² = 892231638148232, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121453) by changing a digit.

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, 362 + ... + 6509.

It is an arithmetic number, because the mean of its divisors is an integer number (2087370).

Almost surely, 2^21121454 is an apocalyptic number.

21121454 is a deficient number, since it is larger than the sum of its proper divisors (12276466).

21121454 is a wasteful number, since it uses less digits than its factorization.

21121454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6955.

The product of its digits is 320, while the sum is 20.

The square root of 21121454 is about 4595.8083075777. The cubic root of 21121454 is about 276.4232723348.

Adding to 21121454 its reverse (45412112), we get a palindrome (66533566).

The spelling of 21121454 in words is "twenty-one million, one hundred twenty-one thousand, four hundred fifty-four".