21145543000 has 32 divisors (see below), whose sum is σ = 49480572960. Its totient is φ = 8458216800.

The previous prime is 21145542961. The next prime is 21145543087. The reversal of 21145543000 is 34554112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10571772 + ... + 10573771.

It is an arithmetic number, because the mean of its divisors is an integer number (1546267905).

Almost surely, 2^21145543000 is an apocalyptic number.

21145543000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21145543000 is an abundant number, since it is smaller than the sum of its proper divisors (28335029960).

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

21145543000 is a wasteful number, since it uses less digits than its factorization.

21145543000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21145564 (or 21145550 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

The spelling of 21145543000 in words is "twenty-one billion, one hundred forty-five million, five hundred forty-three thousand".