20990424 has 96 divisors (see below), whose sum is σ = 65787120. Its totient is φ = 5531904.

The previous prime is 20990423. The next prime is 20990443. The reversal of 20990424 is 42409902.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 20990391 and 20990400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20990423) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14602 + ... + 15974.

Almost surely, 2^20990424 is an apocalyptic number.

20990424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20990424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32893560).

20990424 is an abundant number, since it is smaller than the sum of its proper divisors (44796696).

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

20990424 is a wasteful number, since it uses less digits than its factorization.

20990424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1409 (or 1398 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 20990424 is about 4581.5307485599. The cubic root of 20990424 is about 275.8504756148.

The spelling of 20990424 in words is "twenty million, nine hundred ninety thousand, four hundred twenty-four".