21150420552 has 96 divisors (see below), whose sum is σ = 58417238880. Its totient is φ = 6911773440.

The previous prime is 21150420493. The next prime is 21150420553. The reversal of 21150420552 is 25502405112.

21150420552 is a `hidden beast` number, since 21 + 1 + 50 + 42 + 0 + 552 = 666.

It is not an unprimeable number, because it can be changed into a prime (21150420553) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 769348 + ... + 796364.

It is an arithmetic number, because the mean of its divisors is an integer number (608512905).

Almost surely, 2^21150420552 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 21150420552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29208619440).

21150420552 is an abundant number, since it is smaller than the sum of its proper divisors (37266818328).

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

21150420552 is a wasteful number, since it uses less digits than its factorization.

21150420552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27243 (or 27236 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 27.

Adding to 21150420552 its reverse (25502405112), we get a palindrome (46652825664).

The spelling of 21150420552 in words is "twenty-one billion, one hundred fifty million, four hundred twenty thousand, five hundred fifty-two".