21003236145225 has 36 divisors (see below), whose sum is σ = 37634851082556. Its totient is φ = 11197044618240.

The previous prime is 21003236145217. The next prime is 21003236145233. The reversal of 21003236145225 is 52254163230012.

21003236145225 is a `hidden beast` number, since 2 + 1 + 0 + 0 + 32 + 3 + 614 + 5 + 2 + 2 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (21003236145217) and next prime (21003236145233).

It can be written as a sum of positive squares in 6 ways, for example, as 658517643081 + 20344718502144 = 811491^2 + 4510512^2 .

It is not a de Polignac number, because 21003236145225 - 2³ = 21003236145217 is a prime.

It is a super-2 number, since 2×21003236145225² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21003236145225.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 18965904 + ... + 20042753.

It is an arithmetic number, because the mean of its divisors is an integer number (1045412530071).

Almost surely, 2^{21003236145225} is an apocalyptic number.

21003236145225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21003236145225 is a deficient number, since it is larger than the sum of its proper divisors (16631614937331).

21003236145225 is a wasteful number, since it uses less digits than its factorization.

21003236145225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39011066 (or 39011058 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

Adding to 21003236145225 its reverse (52254163230012), we get a palindrome (73257399375237).

The spelling of 21003236145225 in words is "twenty-one trillion, three billion, two hundred thirty-six million, one hundred forty-five thousand, two hundred twenty-five".