15551150423221 has 32 divisors (see below), whose sum is σ = 18063786958848. Its totient is φ = 13112157199680.

The previous prime is 15551150423143. The next prime is 15551150423273. The reversal of 15551150423221 is 12232405115551.

It is a de Polignac number, because none of the positive numbers 2^k-15551150423221 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 (15551150427221) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 402058135 + ... + 402096811.

It is an arithmetic number, because the mean of its divisors is an integer number (564493342464).

Almost surely, 2^{15551150423221} is an apocalyptic number.

It is an amenable number.

15551150423221 is a deficient number, since it is larger than the sum of its proper divisors (2512636535627).

15551150423221 is an equidigital number, since it uses as much as digits as its factorization.

15551150423221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40561.

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

Adding to 15551150423221 its reverse (12232405115551), we get a palindrome (27783555538772).

The spelling of 15551150423221 in words is "fifteen trillion, five hundred fifty-one billion, one hundred fifty million, four hundred twenty-three thousand, two hundred twenty-one".