20581140 has 24 divisors (see below), whose sum is σ = 57627360. Its totient is φ = 5488288.

The previous prime is 20581103. The next prime is 20581153. The reversal of 20581140 is 4118502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 171450 + ... + 171569.

It is an arithmetic number, because the mean of its divisors is an integer number (2401140).

Almost surely, 2^20581140 is an apocalyptic number.

20581140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20581140 is an abundant number, since it is smaller than the sum of its proper divisors (37046220).

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

20581140 is a wasteful number, since it uses less digits than its factorization.

20581140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343031 (or 343029 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 20581140 is about 4536.6441341591. The cubic root of 20581140 is about 274.0457948214.

Adding to 20581140 its reverse (4118502), we get a palindrome (24699642).

The spelling of 20581140 in words is "twenty million, five hundred eighty-one thousand, one hundred forty".