21530545455240 has 96 divisors (see below), whose sum is σ = 70003298476800. Its totient is φ = 5739097188480.

The previous prime is 21530545455239. The next prime is 21530545455269. The reversal of 21530545455240 is 4255454503512.

21530545455240 is a `hidden beast` number, since 2 + 1 + 5 + 3 + 0 + 5 + 4 + 54 + 552 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

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, 11535000 + ... + 13270919.

It is an arithmetic number, because the mean of its divisors is an integer number (729201025800).

Almost surely, 2^{21530545455240} is an apocalyptic number.

21530545455240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21530545455240 is an abundant number, since it is smaller than the sum of its proper divisors (48472753021560).

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

21530545455240 is a wasteful number, since it uses less digits than its factorization.

21530545455240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24808347 (or 24808340 counting only the distinct ones).

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

Adding to 21530545455240 its reverse (4255454503512), we get a palindrome (25785999958752).

The spelling of 21530545455240 in words is "twenty-one trillion, five hundred thirty billion, five hundred forty-five million, four hundred fifty-five thousand, two hundred forty".