21755531548242 has 24 divisors (see below), whose sum is σ = 47137501405020. Its totient is φ = 7251764405760.

The previous prime is 21755531548193. The next prime is 21755531548243. The reversal of 21755531548242 is 24284513555712.

21755531548242 is a `hidden beast` number, since 2 + 1 + 7 + 5 + 5 + 53 + 1 + 548 + 2 + 42 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 18782524522161 + 2973007026081 = 4333881^2 + 1724241^2 .

It is not an unprimeable number, because it can be changed into a prime (21755531548243) 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, 4919767 + ... + 8228922.

Almost surely, 2^{21755531548242} is an apocalyptic number.

21755531548242 is an abundant number, since it is smaller than the sum of its proper divisors (25381969856778).

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

21755531548242 is a wasteful number, since it uses less digits than its factorization.

21755531548242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13240618 (or 13240615 counting only the distinct ones).

The product of its digits is 13440000, while the sum is 54.

The spelling of 21755531548242 in words is "twenty-one trillion, seven hundred fifty-five billion, five hundred thirty-one million, five hundred forty-eight thousand, two hundred forty-two".