21043543025 has 12 divisors (see below), whose sum is σ = 26124256512. Its totient is φ = 16815309840.

The previous prime is 21043542997. The next prime is 21043543057. The reversal of 21043543025 is 52034534012.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-21043543025 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 466109 + ... + 509258.

It is an arithmetic number, because the mean of its divisors is an integer number (2177021376).

Almost surely, 2^21043543025 is an apocalyptic number.

21043543025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21043543025 is a deficient number, since it is larger than the sum of its proper divisors (5080713487).

21043543025 is an equidigital number, since it uses as much as digits as its factorization.

21043543025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 976240 (or 976235 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 29.

The spelling of 21043543025 in words is "twenty-one billion, forty-three million, five hundred forty-three thousand, twenty-five".