20511140 has 24 divisors (see below), whose sum is σ = 46387320. Its totient is φ = 7573248.

The previous prime is 20511131. The next prime is 20511143. The reversal of 20511140 is 4111502.

It can be written as a sum of positive squares in 4 ways, for example, as 1098304 + 19412836 = 1048^2 + 4406^2 .

It is not an unprimeable number, because it can be changed into a prime (20511143) 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 7 ways as a sum of consecutive naturals, for example, 39185 + ... + 39704.

It is an arithmetic number, because the mean of its divisors is an integer number (1932805).

Almost surely, 2^20511140 is an apocalyptic number.

20511140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20511140 is an abundant number, since it is smaller than the sum of its proper divisors (25876180).

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

20511140 is a wasteful number, since it uses less digits than its factorization.

20511140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78911 (or 78909 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 20511140 is about 4528.9226091864. The cubic root of 20511140 is about 273.7347496074.

Adding to 20511140 its reverse (4111502), we get a palindrome (24622642).

The spelling of 20511140 in words is "twenty million, five hundred eleven thousand, one hundred forty".