21242222820 has 144 divisors (see below), whose sum is σ = 79304359680. Its totient is φ = 4481872128.

The previous prime is 21242222801. The next prime is 21242222839. The reversal of 21242222820 is 2822224212.

It is a happy number.

21242222820 is a `hidden beast` number, since 2 + 12 + 422 + 228 + 2 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21242222801) and next prime (21242222839).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 632040 + ... + 664799.

It is an arithmetic number, because the mean of its divisors is an integer number (550724720).

Almost surely, 2^21242222820 is an apocalyptic number.

21242222820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21242222820 is an abundant number, since it is smaller than the sum of its proper divisors (58062136860).

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

21242222820 is a wasteful number, since it uses less digits than its factorization.

21242222820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1296874 (or 1296869 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 27.

The spelling of 21242222820 in words is "twenty-one billion, two hundred forty-two million, two hundred twenty-two thousand, eight hundred twenty".