1231145252551 has 4 divisors (see below), whose sum is σ = 1231150055472. Its totient is φ = 1231140449632.

The previous prime is 1231145252543. The next prime is 1231145252563. The reversal of 1231145252551 is 1552525411321.

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

It is a cyclic number.

It is not a de Polignac number, because 1231145252551 - 2³ = 1231145252543 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1231145252551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231145252591) 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, 1993906 + ... + 2537311.

It is an arithmetic number, because the mean of its divisors is an integer number (307787513868).

Almost surely, 2^{1231145252551} is an apocalyptic number.

1231145252551 is a deficient number, since it is larger than the sum of its proper divisors (4802921).

1231145252551 is an equidigital number, since it uses as much as digits as its factorization.

1231145252551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4802920.

The product of its digits is 60000, while the sum is 37.

The spelling of 1231145252551 in words is "one trillion, two hundred thirty-one billion, one hundred forty-five million, two hundred fifty-two thousand, five hundred fifty-one".