15551420304221 has 8 divisors (see below), whose sum is σ = 16053437301504. Its totient is φ = 15049425699360.

The previous prime is 15551420304137. The next prime is 15551420304281. The reversal of 15551420304221 is 12240302415551.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 15551420304221 - 2³⁰ = 15550346562397 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 (15551420304281) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4181000 + ... + 6970193.

It is an arithmetic number, because the mean of its divisors is an integer number (2006679662688).

Almost surely, 2^{15551420304221} is an apocalyptic number.

It is an amenable number.

15551420304221 is a deficient number, since it is larger than the sum of its proper divisors (502016997283).

15551420304221 is a wasteful number, since it uses less digits than its factorization.

15551420304221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11196211.

The product of its (nonzero) digits is 48000, while the sum is 35.

Adding to 15551420304221 its reverse (12240302415551), we get a palindrome (27791722719772).

The spelling of 15551420304221 in words is "fifteen trillion, five hundred fifty-one billion, four hundred twenty million, three hundred four thousand, two hundred twenty-one".