21455160663540 has 48 divisors (see below), whose sum is σ = 60635893332672. Its totient is φ = 5667905369856.

The previous prime is 21455160663527. The next prime is 21455160663557. The reversal of 21455160663540 is 4536606155412.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21455160663540.

It is a congruent number.

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, 1670956249 + ... + 1670969088.

It is an arithmetic number, because the mean of its divisors is an integer number (1263247777764).

Almost surely, 2^{21455160663540} is an apocalyptic number.

21455160663540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21455160663540 is an abundant number, since it is smaller than the sum of its proper divisors (39180732669132).

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

21455160663540 is a wasteful number, since it uses less digits than its factorization.

21455160663540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3341925456 (or 3341925454 counting only the distinct ones).

The product of its (nonzero) digits is 2592000, while the sum is 48.

The spelling of 21455160663540 in words is "twenty-one trillion, four hundred fifty-five billion, one hundred sixty million, six hundred sixty-three thousand, five hundred forty".