21145543644500 has 96 divisors (see below), whose sum is σ = 53343761417856. Its totient is φ = 7236977472000.

The previous prime is 21145543644473. The next prime is 21145543644523. The reversal of 21145543644500 is 544634554112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 112984274 + ... + 113171273.

It is an arithmetic number, because the mean of its divisors is an integer number (555664181436).

Almost surely, 2^{21145543644500} is an apocalyptic number.

21145543644500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21145543644500 is an abundant number, since it is smaller than the sum of its proper divisors (32198217773356).

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

21145543644500 is a wasteful number, since it uses less digits than its factorization.

21145543644500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226155594 (or 226155582 counting only the distinct ones).

The product of its (nonzero) digits is 1152000, while the sum is 44.

The spelling of 21145543644500 in words is "twenty-one trillion, one hundred forty-five billion, five hundred forty-three million, six hundred forty-four thousand, five hundred".