21050040552 has 64 divisors (see below), whose sum is σ = 53553000960. Its totient is φ = 6893241600.

The previous prime is 21050040521. The next prime is 21050040589. The reversal of 21050040552 is 25504005012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1255102 + ... + 1271762.

It is an arithmetic number, because the mean of its divisors is an integer number (836765640).

Almost surely, 2^21050040552 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 21050040552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26776500480).

21050040552 is an abundant number, since it is smaller than the sum of its proper divisors (32502960408).

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

21050040552 is a wasteful number, since it uses less digits than its factorization.

21050040552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17594 (or 17590 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 24.

Adding to 21050040552 its reverse (25504005012), we get a palindrome (46554045564).

The spelling of 21050040552 in words is "twenty-one billion, fifty million, forty thousand, five hundred fifty-two".