21954288 has 20 divisors (see below), whose sum is σ = 56715368. Its totient is φ = 7318080.

The previous prime is 21954287. The next prime is 21954299. The reversal of 21954288 is 88245912.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21954281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 228643 + ... + 228738.

Almost surely, 2^21954288 is an apocalyptic number.

It is an amenable number.

21954288 is an abundant number, since it is smaller than the sum of its proper divisors (34761080).

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

21954288 is a wasteful number, since it uses less digits than its factorization.

21954288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 457392 (or 457386 counting only the distinct ones).

The product of its digits is 46080, while the sum is 39.

The square root of 21954288 is about 4685.5403103591. The cubic root of 21954288 is about 280.0097275532.

The spelling of 21954288 in words is "twenty-one million, nine hundred fifty-four thousand, two hundred eighty-eight".