20919420 has 144 divisors (see below), whose sum is σ = 68769792. Its totient is φ = 5132160.

The previous prime is 20919419. The next prime is 20919421. The reversal of 20919420 is 2491902.

It is an interprime number because it is at equal distance from previous prime (20919419) and next prime (20919421).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20919421) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 128259 + ... + 128421.

It is an arithmetic number, because the mean of its divisors is an integer number (477568).

Almost surely, 2^20919420 is an apocalyptic number.

20919420 is a gapful number since it is divisible by the number (20) 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 20919420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34384896).

20919420 is an abundant number, since it is smaller than the sum of its proper divisors (47850372).

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

20919420 is a wasteful number, since it uses less digits than its factorization.

20919420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232 (or 227 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 20919420 is about 4573.7752458992. The cubic root of 20919420 is about 275.5390857839.

It can be divided in two parts, 2091 and 9420, that added together give a palindrome (11511).

The spelling of 20919420 in words is "twenty million, nine hundred nineteen thousand, four hundred twenty".