21522012444 has 96 divisors (see below), whose sum is σ = 60676983360. Its totient is φ = 6569496576.

The previous prime is 21522012439. The next prime is 21522012451. The reversal of 21522012444 is 44421022512.

It is a happy number.

21522012444 is a `hidden beast` number, since 2 + 15 + 2 + 201 + 2 + 444 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 90477 + ... + 226340.

It is an arithmetic number, because the mean of its divisors is an integer number (632051910).

Almost surely, 2^21522012444 is an apocalyptic number.

It is an amenable number.

21522012444 is an abundant number, since it is smaller than the sum of its proper divisors (39154970916).

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

21522012444 is a wasteful number, since it uses less digits than its factorization.

21522012444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316884 (or 316876 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 27.

Adding to 21522012444 its reverse (44421022512), we get a palindrome (65943034956).

The spelling of 21522012444 in words is "twenty-one billion, five hundred twenty-two million, twelve thousand, four hundred forty-four".