21597468 has 24 divisors (see below), whose sum is σ = 50493072. Its totient is φ = 7185024.

The previous prime is 21597467. The next prime is 21597473. The reversal of 21597468 is 86479512.

It is a super-2 number, since 2×21597468² = 932901248022048, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21597467) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5946 + ... + 8862.

It is an arithmetic number, because the mean of its divisors is an integer number (2103878).

Almost surely, 2^21597468 is an apocalyptic number.

It is an amenable number.

21597468 is an abundant number, since it is smaller than the sum of its proper divisors (28895604).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21597468 is a wasteful number, since it uses less digits than its factorization.

21597468 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3541 (or 3539 counting only the distinct ones).

The product of its digits is 120960, while the sum is 42.

The square root of 21597468 is about 4647.3076076369. The cubic root of 21597468 is about 278.4844476444.

The spelling of 21597468 in words is "twenty-one million, five hundred ninety-seven thousand, four hundred sixty-eight".