21957459 has 8 divisors (see below), whose sum is σ = 29336832. Its totient is φ = 14608200.

The previous prime is 21957431. The next prime is 21957473. The reversal of 21957459 is 95475912.

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

It is not a de Polignac number, because 21957459 - 2¹¹ = 21955411 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21957459.

It is not an unprimeable number, because it can be changed into a prime (21957409) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 5767 + ... + 8784.

It is an arithmetic number, because the mean of its divisors is an integer number (3667104).

Almost surely, 2^21957459 is an apocalyptic number.

21957459 is a deficient number, since it is larger than the sum of its proper divisors (7379373).

21957459 is a wasteful number, since it uses less digits than its factorization.

21957459 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15057.

The product of its digits is 113400, while the sum is 42.

The square root of 21957459 is about 4685.8786796075. The cubic root of 21957459 is about 280.0232081103.

The spelling of 21957459 in words is "twenty-one million, nine hundred fifty-seven thousand, four hundred fifty-nine".