1251540401105 has 4 divisors (see below), whose sum is σ = 1501848481332. Its totient is φ = 1001232320880.

The previous prime is 1251540401087. The next prime is 1251540401119. The reversal of 1251540401105 is 5011040451521.

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 504918251776 + 746622149329 = 710576^2 + 864073^2 .

It is not a de Polignac number, because 1251540401105 - 2²⁸ = 1251271965649 is a prime.

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, 125154040106 + ... + 125154040115.

It is an arithmetic number, because the mean of its divisors is an integer number (375462120333).

Almost surely, 2^{1251540401105} is an apocalyptic number.

It is an amenable number.

1251540401105 is a deficient number, since it is larger than the sum of its proper divisors (250308080227).

1251540401105 is an equidigital number, since it uses as much as digits as its factorization.

1251540401105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250308080226.

The product of its (nonzero) digits is 4000, while the sum is 29.

Adding to 1251540401105 its reverse (5011040451521), we get a palindrome (6262580852626).

The spelling of 1251540401105 in words is "one trillion, two hundred fifty-one billion, five hundred forty million, four hundred one thousand, one hundred five".