20898540 has 144 divisors (see below), whose sum is σ = 70711200. Its totient is φ = 5121792.

The previous prime is 20898533. The next prime is 20898569. The reversal of 20898540 is 4589802.

20898540 is a `hidden beast` number, since 20 + 8 + 98 + 540 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20898495 and 20898504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 91146 + ... + 91374.

It is an arithmetic number, because the mean of its divisors is an integer number (491050).

Almost surely, 2^20898540 is an apocalyptic number.

20898540 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 20898540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35355600).

20898540 is an abundant number, since it is smaller than the sum of its proper divisors (49812660).

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

20898540 is a wasteful number, since it uses less digits than its factorization.

20898540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273 (or 252 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 20898540 is about 4571.4920977729. The cubic root of 20898540 is about 275.4473819777.

The spelling of 20898540 in words is "twenty million, eight hundred ninety-eight thousand, five hundred forty".