20153540 has 48 divisors (see below), whose sum is σ = 46678464. Its totient is φ = 7248000.

The previous prime is 20153531. The next prime is 20153561. The reversal of 20153540 is 4535102.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21767 + ... + 22673.

It is an arithmetic number, because the mean of its divisors is an integer number (972468).

Almost surely, 2^20153540 is an apocalyptic number.

20153540 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 20153540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23339232).

20153540 is an abundant number, since it is smaller than the sum of its proper divisors (26524924).

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

20153540 is a wasteful number, since it uses less digits than its factorization.

20153540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1028 (or 1026 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 20153540 is about 4489.2694283146. The cubic root of 20153540 is about 272.1346111389.

Adding to 20153540 its reverse (4535102), we get a palindrome (24688642).

It can be divided in two parts, 2015 and 3540, that added together give a palindrome (5555).

The spelling of 20153540 in words is "twenty million, one hundred fifty-three thousand, five hundred forty".