1251312211345 has 24 divisors (see below), whose sum is σ = 1779686881704. Its totient is φ = 841853166336.

The previous prime is 1251312211343. The next prime is 1251312211367. The reversal of 1251312211345 is 5431122131521.

It can be written as a sum of positive squares in 4 ways, for example, as 464584012816 + 786728198529 = 681604^2 + 886977^2 .

It is not a de Polignac number, because 1251312211345 - 2¹ = 1251312211343 is a prime.

It is a super-2 number, since 2×1251312211345² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1251312211343) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 48170004 + ... + 48195973.

It is an arithmetic number, because the mean of its divisors is an integer number (74153620071).

Almost surely, 2^{1251312211345} is an apocalyptic number.

It is an amenable number.

1251312211345 is a deficient number, since it is larger than the sum of its proper divisors (528374670359).

1251312211345 is an equidigital number, since it uses as much as digits as its factorization.

1251312211345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96366049 (or 96366042 counting only the distinct ones).

The product of its digits is 7200, while the sum is 31.

Adding to 1251312211345 its reverse (5431122131521), we get a palindrome (6682434342866).

The spelling of 1251312211345 in words is "one trillion, two hundred fifty-one billion, three hundred twelve million, two hundred eleven thousand, three hundred forty-five".