21954249 has 12 divisors (see below), whose sum is σ = 31828212. Its totient is φ = 14582400.

The previous prime is 21954241. The next prime is 21954263. The reversal of 21954249 is 94245912.

It can be written as a sum of positive squares in 2 ways, for example, as 16548624 + 5405625 = 4068^2 + 2325^2 .

It is not a de Polignac number, because 21954249 - 2³ = 21954241 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21954241) 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, 1812 + ... + 6869.

It is an arithmetic number, because the mean of its divisors is an integer number (2652351).

Almost surely, 2^21954249 is an apocalyptic number.

It is an amenable number.

21954249 is a deficient number, since it is larger than the sum of its proper divisors (9873963).

21954249 is a wasteful number, since it uses less digits than its factorization.

21954249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8968 (or 8965 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 21954249 is about 4685.5361486174. The cubic root of 21954249 is about 280.0095617483.

The spelling of 21954249 in words is "twenty-one million, nine hundred fifty-four thousand, two hundred forty-nine".