21954447 has 12 divisors (see below), whose sum is σ = 31783440. Its totient is φ = 14603328.

The previous prime is 21954403. The next prime is 21954461. The reversal of 21954447 is 74445912.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-21954447 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

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

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1879 + ... + 6887.

It is an arithmetic number, because the mean of its divisors is an integer number (2648620).

Almost surely, 2^21954447 is an apocalyptic number.

21954447 is a deficient number, since it is larger than the sum of its proper divisors (9828993).

21954447 is a wasteful number, since it uses less digits than its factorization.

21954447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5502 (or 5499 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 21954447 is about 4685.5572774218. The cubic root of 21954447 is about 280.0104035250.

The spelling of 21954447 in words is "twenty-one million, nine hundred fifty-four thousand, four hundred forty-seven".