20917424 has 40 divisors (see below), whose sum is σ = 44552208. Its totient is φ = 9434880.

The previous prime is 20917409. The next prime is 20917441. The reversal of 20917424 is 42471902.

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 in 7 ways as a sum of consecutive naturals, for example, 27254 + ... + 28010.

Almost surely, 2^20917424 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 20917424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22276104).

20917424 is an abundant number, since it is smaller than the sum of its proper divisors (23634784).

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

20917424 is a wasteful number, since it uses less digits than its factorization.

20917424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 933 (or 927 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 20917424 is about 4573.5570402040. The cubic root of 20917424 is about 275.5303221007.

The spelling of 20917424 in words is "twenty million, nine hundred seventeen thousand, four hundred twenty-four".