1291439052225 has 243 divisors, whose sum is σ = 2745290557737. Its totient is φ = 578644335360.

The previous prime is 1291439052217. The next prime is 1291439052247. The reversal of 1291439052225 is 5222509341921.

The square root of 1291439052225 is 1136415.

It is a perfect power (a square), and thus also a powerful number.

1291439052225 is a `hidden beast` number, since 1 + 2 + 9 + 14 + 3 + 90 + 522 + 25 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 3767872689 + 1287671179536 = 61383^2 + 1134756^2 .

It is not a de Polignac number, because 1291439052225 - 2³ = 1291439052217 is a prime.

It is a super-2 number, since 2×1291439052225² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 9426562357 + ... + 9426562493.

Almost surely, 2^{1291439052225} is an apocalyptic number.

1291439052225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1291439052225 is the 1136415-th square number.

1291439052225 is the 568208-th centered octagonal number.

It is an amenable number.

1291439052225 is an abundant number, since it is smaller than the sum of its proper divisors (1453851505512).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1291439052225 is an equidigital number, since it uses as much as digits as its factorization.

1291439052225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 462 (or 231 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The spelling of 1291439052225 in words is "one trillion, two hundred ninety-one billion, four hundred thirty-nine million, fifty-two thousand, two hundred twenty-five".