21957422 has 4 divisors (see below), whose sum is σ = 32936136. Its totient is φ = 10978710.

The previous prime is 21957409. The next prime is 21957431. The reversal of 21957422 is 22475912.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5489354 + ... + 5489357.

It is an arithmetic number, because the mean of its divisors is an integer number (8234034).

Almost surely, 2^21957422 is an apocalyptic number.

21957422 is a deficient number, since it is larger than the sum of its proper divisors (10978714).

21957422 is a wasteful number, since it uses less digits than its factorization.

21957422 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10978713.

The product of its digits is 10080, while the sum is 32.

The square root of 21957422 is about 4685.8747315736. The cubic root of 21957422 is about 280.0230508234.

The spelling of 21957422 in words is "twenty-one million, nine hundred fifty-seven thousand, four hundred twenty-two".