21545534340 has 144 divisors (see below), whose sum is σ = 73754815680. Its totient is φ = 5043037440.

The previous prime is 21545534321. The next prime is 21545534359. The reversal of 21545534340 is 4343554512.

21545534340 is a `hidden beast` number, since 21 + 5 + 4 + 553 + 43 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (21545534321) and next prime (21545534359).

It is a super-2 number, since 2×21545534340² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21545534295 and 21545534304.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 130194 + ... + 245033.

It is an arithmetic number, because the mean of its divisors is an integer number (512186220).

Almost surely, 2^21545534340 is an apocalyptic number.

21545534340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21545534340 is an abundant number, since it is smaller than the sum of its proper divisors (52209281340).

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

21545534340 is a wasteful number, since it uses less digits than its factorization.

21545534340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375282 (or 375277 counting only the distinct ones).

The product of its (nonzero) digits is 144000, while the sum is 36.

The spelling of 21545534340 in words is "twenty-one billion, five hundred forty-five million, five hundred thirty-four thousand, three hundred forty".