20021221240 has 32 divisors (see below), whose sum is σ = 47006347680. Its totient is φ = 7660292992.

The previous prime is 20021221211. The next prime is 20021221277. The reversal of 20021221240 is 4212212002.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10880179 + ... + 10882018.

It is an arithmetic number, because the mean of its divisors is an integer number (1468948365).

Almost surely, 2^20021221240 is an apocalyptic number.

20021221240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20021221240 is an abundant number, since it is smaller than the sum of its proper divisors (26985126440).

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

20021221240 is a wasteful number, since it uses less digits than its factorization.

20021221240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21762231 (or 21762227 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 20021221240 its reverse (4212212002), we get a palindrome (24233433242).

The spelling of 20021221240 in words is "twenty billion, twenty-one million, two hundred twenty-one thousand, two hundred forty".