21035845825 has 6 divisors (see below), whose sum is σ = 26084448854. Its totient is φ = 16828676640.

The previous prime is 21035845813. The next prime is 21035845843. The reversal of 21035845825 is 52854853012.

It can be written as a sum of positive squares in 3 ways, for example, as 1383170481 + 19652675344 = 37191^2 + 140188^2 .

It is not a de Polignac number, because 21035845825 - 2²⁵ = 21002291393 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 420716892 + ... + 420716941.

Almost surely, 2^21035845825 is an apocalyptic number.

21035845825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21035845825 is a deficient number, since it is larger than the sum of its proper divisors (5048603029).

21035845825 is an equidigital number, since it uses as much as digits as its factorization.

21035845825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 841433843 (or 841433838 counting only the distinct ones).

The product of its (nonzero) digits is 384000, while the sum is 43.

The spelling of 21035845825 in words is "twenty-one billion, thirty-five million, eight hundred forty-five thousand, eight hundred twenty-five".