21697848 has 128 divisors (see below), whose sum is σ = 67392000. Its totient is φ = 6428160.

The previous prime is 21697847. The next prime is 21697853. The reversal of 21697848 is 84879612.

It is a super-2 number, since 2×21697848² = 941593215662208, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21697847) 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 31 ways as a sum of consecutive naturals, for example, 69613 + ... + 69923.

It is an arithmetic number, because the mean of its divisors is an integer number (526500).

Almost surely, 2^21697848 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21697848, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33696000).

21697848 is an abundant number, since it is smaller than the sum of its proper divisors (45694152).

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

21697848 is a wasteful number, since it uses less digits than its factorization.

21697848 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362 (or 352 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 21697848 is about 4658.0948895444. The cubic root of 21697848 is about 278.9152245612.

The spelling of 21697848 in words is "twenty-one million, six hundred ninety-seven thousand, eight hundred forty-eight".