1251312153205 has 4 divisors (see below), whose sum is σ = 1501574583852. Its totient is φ = 1001049722560.

The previous prime is 1251312153181. The next prime is 1251312153209. The reversal of 1251312153205 is 5023512131521.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 789400264324 + 461911888881 = 888482^2 + 679641^2 .

It is not a de Polignac number, because 1251312153205 - 2¹⁵ = 1251312120437 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1251312153209) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 125131215316 + ... + 125131215325.

It is an arithmetic number, because the mean of its divisors is an integer number (375393645963).

Almost surely, 2^{1251312153205} is an apocalyptic number.

It is an amenable number.

1251312153205 is a deficient number, since it is larger than the sum of its proper divisors (250262430647).

1251312153205 is an equidigital number, since it uses as much as digits as its factorization.

1251312153205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250262430646.

The product of its (nonzero) digits is 9000, while the sum is 31.

Adding to 1251312153205 its reverse (5023512131521), we get a palindrome (6274824284726).

The spelling of 1251312153205 in words is "one trillion, two hundred fifty-one billion, three hundred twelve million, one hundred fifty-three thousand, two hundred five".