20405353520225 has 6 divisors (see below), whose sum is σ = 25302638365110. Its totient is φ = 16324282816160.

The previous prime is 20405353520183. The next prime is 20405353520243. The reversal of 20405353520225 is 52202535350402.

It can be written as a sum of positive squares in 3 ways, for example, as 1195514812816 + 19209838707409 = 1093396^2 + 4382903^2 .

It is not a de Polignac number, because 20405353520225 - 2⁶ = 20405353520161 is a prime.

It is a super-4 number, since 4×20405353520225⁴ (a number of 54 digits) contains 4444 as substring.

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, 408107070380 + ... + 408107070429.

It is an arithmetic number, because the mean of its divisors is an integer number (4217106394185).

Almost surely, 2^{20405353520225} is an apocalyptic number.

20405353520225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20405353520225 is a deficient number, since it is larger than the sum of its proper divisors (4897284844885).

20405353520225 is an equidigital number, since it uses as much as digits as its factorization.

20405353520225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 816214140819 (or 816214140814 counting only the distinct ones).

The product of its (nonzero) digits is 360000, while the sum is 38.

Adding to 20405353520225 its reverse (52202535350402), we get a palindrome (72607888870627).

The spelling of 20405353520225 in words is "twenty trillion, four hundred five billion, three hundred fifty-three million, five hundred twenty thousand, two hundred twenty-five".