21055245152 has 48 divisors (see below), whose sum is σ = 42493429440. Its totient is φ = 10264152192.

The previous prime is 21055245131. The next prime is 21055245193. The reversal of 21055245152 is 25154255012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (32).

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, 761099 + ... + 788277.

It is an arithmetic number, because the mean of its divisors is an integer number (885279780).

Almost surely, 2^21055245152 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21055245152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21246714720).

21055245152 is an abundant number, since it is smaller than the sum of its proper divisors (21438184288).

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

21055245152 is a wasteful number, since it uses less digits than its factorization.

21055245152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27795 (or 27787 counting only the distinct ones).

The product of its (nonzero) digits is 20000, while the sum is 32.

The spelling of 21055245152 in words is "twenty-one billion, fifty-five million, two hundred forty-five thousand, one hundred fifty-two".