20541840 has 160 divisors (see below), whose sum is σ = 71995392. Its totient is φ = 4800000.

The previous prime is 20541839. The next prime is 20541841. The reversal of 20541840 is 4814502.

It is an interprime number because it is at equal distance from previous prime (20541839) and next prime (20541841).

It is a hoax number, since the sum of its digits (24) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20541840.

It is not an unprimeable number, because it can be changed into a prime (20541841) 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, 81715 + ... + 81965.

Almost surely, 2^20541840 is an apocalyptic number.

20541840 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 20541840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35997696).

20541840 is an abundant number, since it is smaller than the sum of its proper divisors (51453552).

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

20541840 is a wasteful number, since it uses less digits than its factorization.

20541840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309 (or 303 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 20541840 is about 4532.3106689635. The cubic root of 20541840 is about 273.8712521385.

The spelling of 20541840 in words is "twenty million, five hundred forty-one thousand, eight hundred forty".