21220756252 has 24 divisors (see below), whose sum is σ = 39243007440. Its totient is φ = 10012815360.

The previous prime is 21220756241. The next prime is 21220756289. The reversal of 21220756252 is 25265702212.

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 7 ways as a sum of consecutive naturals, for example, 523699 + ... + 562762.

It is an arithmetic number, because the mean of its divisors is an integer number (1635125310).

Almost surely, 2^21220756252 is an apocalyptic number.

It is an amenable number.

21220756252 is a deficient number, since it is larger than the sum of its proper divisors (18022251188).

21220756252 is a wasteful number, since it uses less digits than its factorization.

21220756252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1086741 (or 1086739 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 34.

The spelling of 21220756252 in words is "twenty-one billion, two hundred twenty million, seven hundred fifty-six thousand, two hundred fifty-two".