21954242 has 8 divisors (see below), whose sum is σ = 34868556. Its totient is φ = 10331392.

The previous prime is 21954241. The next prime is 21954263. The reversal of 21954242 is 24245912.

It can be written as a sum of positive squares in 2 ways, for example, as 20511841 + 1442401 = 4529^2 + 1201^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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 3 ways as a sum of consecutive naturals, for example, 322823 + ... + 322890.

Almost surely, 2^21954242 is an apocalyptic number.

21954242 is a deficient number, since it is larger than the sum of its proper divisors (12914314).

21954242 is a wasteful number, since it uses less digits than its factorization.

21954242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645732.

The product of its digits is 5760, while the sum is 29.

The square root of 21954242 is about 4685.5354016377. The cubic root of 21954242 is about 280.0095319884.

The spelling of 21954242 in words is "twenty-one million, nine hundred fifty-four thousand, two hundred forty-two".