1551234321551 has 4 divisors (see below), whose sum is σ = 1551435344472. Its totient is φ = 1551033298632.

The previous prime is 1551234321541. The next prime is 1551234321557.

1551234321551 is nontrivially palindromic in base 10.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1551234321551 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 (1551234321557) 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, 100499885 + ... + 100515318.

It is an arithmetic number, because the mean of its divisors is an integer number (387858836118).

Almost surely, 2^{1551234321551} is an apocalyptic number.

1551234321551 is a deficient number, since it is larger than the sum of its proper divisors (201022921).

1551234321551 is an equidigital number, since it uses as much as digits as its factorization.

1551234321551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201022920.

The product of its digits is 90000, while the sum is 38.

The spelling of 1551234321551 in words is "one trillion, five hundred fifty-one billion, two hundred thirty-four million, three hundred twenty-one thousand, five hundred fifty-one".