21553405552242 has 24 divisors (see below), whose sum is σ = 49446048032316. Its totient is φ = 6761852722176.

The previous prime is 21553405552213. The next prime is 21553405552247. The reversal of 21553405552242 is 24225550435512.

21553405552242 is a `hidden beast` number, since 2 + 1 + 5 + 5 + 34 + 0 + 55 + 522 + 42 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 21161205217161 + 392200335081 = 4600131^2 + 626259^2 .

It is not an unprimeable number, because it can be changed into a prime (21553405552247) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35217982623 + ... + 35217983234.

Almost surely, 2^{21553405552242} is an apocalyptic number.

21553405552242 is an abundant number, since it is smaller than the sum of its proper divisors (27892642480074).

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

21553405552242 is a wasteful number, since it uses less digits than its factorization.

21553405552242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70435965882 (or 70435965879 counting only the distinct ones).

The product of its (nonzero) digits is 2400000, while the sum is 45.

Adding to 21553405552242 its reverse (24225550435512), we get a palindrome (45778955987754).

The spelling of 21553405552242 in words is "twenty-one trillion, five hundred fifty-three billion, four hundred five million, five hundred fifty-two thousand, two hundred forty-two".