20461540 has 48 divisors (see below), whose sum is σ = 49641984. Its totient is φ = 7001600.

The previous prime is 20461517. The next prime is 20461541. The reversal of 20461540 is 4516402.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (20461541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1005 + ... + 6475.

It is an arithmetic number, because the mean of its divisors is an integer number (1034208).

Almost surely, 2^20461540 is an apocalyptic number.

20461540 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 20461540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24820992).

20461540 is an abundant number, since it is smaller than the sum of its proper divisors (29180444).

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

20461540 is a wasteful number, since it uses less digits than its factorization.

20461540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5508 (or 5506 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 20461540 is about 4523.4433786663. The cubic root of 20461540 is about 273.5139232262.

Adding to 20461540 its reverse (4516402), we get a palindrome (24977942).

The spelling of 20461540 in words is "twenty million, four hundred sixty-one thousand, five hundred forty".