21534469025 has 6 divisors (see below), whose sum is σ = 26702741622. Its totient is φ = 17227575200.

The previous prime is 21534469009. The next prime is 21534469031. The reversal of 21534469025 is 52096443512.

It can be written as a sum of positive squares in 3 ways, for example, as 667489 + 21533801536 = 817^2 + 146744^2 .

It is not a de Polignac number, because 21534469025 - 2⁴ = 21534469009 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 430689356 + ... + 430689405.

It is an arithmetic number, because the mean of its divisors is an integer number (4450456937).

Almost surely, 2^21534469025 is an apocalyptic number.

21534469025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21534469025 is a deficient number, since it is larger than the sum of its proper divisors (5168272597).

21534469025 is an equidigital number, since it uses as much as digits as its factorization.

21534469025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 861378771 (or 861378766 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 41.

The spelling of 21534469025 in words is "twenty-one billion, five hundred thirty-four million, four hundred sixty-nine thousand, twenty-five".