21954481 has 4 divisors (see below), whose sum is σ = 23110000. Its totient is φ = 20798964.

The previous prime is 21954461. The next prime is 21954487. The reversal of 21954481 is 18445912.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21954481 - 2⁹ = 21953969 is a prime.

It is a super-2 number, since 2×21954481² = 963998471958722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21954487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 577731 + ... + 577768.

It is an arithmetic number, because the mean of its divisors is an integer number (5777500).

Almost surely, 2^21954481 is an apocalyptic number.

It is an amenable number.

21954481 is a deficient number, since it is larger than the sum of its proper divisors (1155519).

21954481 is a wasteful number, since it uses less digits than its factorization.

21954481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1155518.

The product of its digits is 11520, while the sum is 34.

The square root of 21954481 is about 4685.5609055907. The cubic root of 21954481 is about 280.0105480720.

The spelling of 21954481 in words is "twenty-one million, nine hundred fifty-four thousand, four hundred eighty-one".