21954624 has 56 divisors (see below), whose sum is σ = 60106560. Its totient is φ = 7064064.

The previous prime is 21954623. The next prime is 21954629. The reversal of 21954624 is 42645912.

It is not an unprimeable number, because it can be changed into a prime (21954623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3597 + ... + 7539.

Almost surely, 2^21954624 is an apocalyptic number.

21954624 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21954624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30053280).

21954624 is an abundant number, since it is smaller than the sum of its proper divisors (38151936).

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

21954624 is a wasteful number, since it uses less digits than its factorization.

21954624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3987 (or 3977 counting only the distinct ones).

The product of its digits is 17280, while the sum is 33.

The square root of 21954624 is about 4685.5761652117. The cubic root of 21954624 is about 280.0111560181.

It can be divided in two parts, 21954 and 624, that added together give a triangular number (22578 = T₂₁₂).

The spelling of 21954624 in words is "twenty-one million, nine hundred fifty-four thousand, six hundred twenty-four".