21156370752 has 112 divisors (see below), whose sum is σ = 61103572992. Its totient is φ = 6406970880.

The previous prime is 21156370747. The next prime is 21156370757. The reversal of 21156370752 is 25707365112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21156370747) and next prime (21156370757).

It is a self number, because there is not a number n which added to its sum of digits gives 21156370752.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21156370757) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6678673 + ... + 6681839.

It is an arithmetic number, because the mean of its divisors is an integer number (545567616).

Almost surely, 2^21156370752 is an apocalyptic number.

21156370752 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21156370752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30551786496).

21156370752 is an abundant number, since it is smaller than the sum of its proper divisors (39947202240).

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

21156370752 is a wasteful number, since it uses less digits than its factorization.

21156370752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6356 (or 6346 counting only the distinct ones).

The product of its (nonzero) digits is 88200, while the sum is 39.

The spelling of 21156370752 in words is "twenty-one billion, one hundred fifty-six million, three hundred seventy thousand, seven hundred fifty-two".