21954172 has 12 divisors (see below), whose sum is σ = 39458440. Its totient is φ = 10680336.

The previous prime is 21954161. The next prime is 21954173. The reversal of 21954172 is 27145912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21954173) 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, 74022 + ... + 74317.

Almost surely, 2^21954172 is an apocalyptic number.

It is an amenable number.

21954172 is a deficient number, since it is larger than the sum of its proper divisors (17504268).

21954172 is a wasteful number, since it uses less digits than its factorization.

21954172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148380 (or 148378 counting only the distinct ones).

The product of its digits is 5040, while the sum is 31.

The square root of 21954172 is about 4685.5279318344. The cubic root of 21954172 is about 280.0092343893.

The spelling of 21954172 in words is "twenty-one million, nine hundred fifty-four thousand, one hundred seventy-two".