20511350221440 has 256 divisors, whose sum is σ = 71400838521600. Its totient is φ = 4977835376640.

The previous prime is 20511350221423. The next prime is 20511350221447. The reversal of 20511350221440 is 4412205311502.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 20511350221398 and 20511350221407.

It is not an unprimeable number, because it can be changed into a prime (20511350221447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4014945 + ... + 7559264.

It is an arithmetic number, because the mean of its divisors is an integer number (278909525475).

Almost surely, 2^{20511350221440} is an apocalyptic number.

20511350221440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20511350221440 is an abundant number, since it is smaller than the sum of its proper divisors (50889488300160).

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

20511350221440 is a wasteful number, since it uses less digits than its factorization.

20511350221440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11574315 (or 11574303 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 30.

Adding to 20511350221440 its reverse (4412205311502), we get a palindrome (24923555532942).

The spelling of 20511350221440 in words is "twenty trillion, five hundred eleven billion, three hundred fifty million, two hundred twenty-one thousand, four hundred forty".