1551541242421 has 4 divisors (see below), whose sum is σ = 1551546808812. Its totient is φ = 1551535676032.

The previous prime is 1551541242409. The next prime is 1551541242443. The reversal of 1551541242421 is 1242421451551.

It is a happy number.

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 1330363855396 + 221177387025 = 1153414^2 + 470295^2 .

It is a cyclic number.

It is not a de Polignac number, because 1551541242421 - 2¹¹ = 1551541240373 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 (1551541242491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2341756 + ... + 2930341.

It is an arithmetic number, because the mean of its divisors is an integer number (387886702203).

Almost surely, 2^{1551541242421} is an apocalyptic number.

It is an amenable number.

1551541242421 is a deficient number, since it is larger than the sum of its proper divisors (5566391).

1551541242421 is an equidigital number, since it uses as much as digits as its factorization.

1551541242421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5566390.

The product of its digits is 64000, while the sum is 37.

Adding to 1551541242421 its reverse (1242421451551), we get a palindrome (2793962693972).

The spelling of 1551541242421 in words is "one trillion, five hundred fifty-one billion, five hundred forty-one million, two hundred forty-two thousand, four hundred twenty-one".