1251423305105 has 4 divisors (see below), whose sum is σ = 1501707966132. Its totient is φ = 1001138644080.

The previous prime is 1251423305057. The next prime is 1251423305147. The reversal of 1251423305105 is 5015033241521.

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 656710882129 + 594712422976 = 810377^2 + 771176^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1251423305105 is a prime.

It is a super-2 number, since 2×1251423305105² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 125142330506 + ... + 125142330515.

It is an arithmetic number, because the mean of its divisors is an integer number (375426991533).

Almost surely, 2^{1251423305105} is an apocalyptic number.

It is an amenable number.

1251423305105 is a deficient number, since it is larger than the sum of its proper divisors (250284661027).

1251423305105 is an equidigital number, since it uses as much as digits as its factorization.

1251423305105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250284661026.

The product of its (nonzero) digits is 18000, while the sum is 32.

Adding to 1251423305105 its reverse (5015033241521), we get a palindrome (6266456546626).

The spelling of 1251423305105 in words is "one trillion, two hundred fifty-one billion, four hundred twenty-three million, three hundred five thousand, one hundred five".