155040123436221 has 16 divisors (see below), whose sum is σ = 207059931316544. Its totient is φ = 103190203062144.

The previous prime is 155040123436189. The next prime is 155040123436241. The reversal of 155040123436221 is 122634321040551.

It is not a de Polignac number, because 155040123436221 - 2⁵ = 155040123436189 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 155040123436221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155040123436241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 163616025 + ... + 164560881.

It is an arithmetic number, because the mean of its divisors is an integer number (12941245707284).

Almost surely, 2^{155040123436221} is an apocalyptic number.

It is an amenable number.

155040123436221 is a deficient number, since it is larger than the sum of its proper divisors (52019807880323).

155040123436221 is an equidigital number, since it uses as much as digits as its factorization.

155040123436221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1034700.

The product of its (nonzero) digits is 172800, while the sum is 39.

Adding to 155040123436221 its reverse (122634321040551), we get a palindrome (277674444476772).

The spelling of 155040123436221 in words is "one hundred fifty-five trillion, forty billion, one hundred twenty-three million, four hundred thirty-six thousand, two hundred twenty-one".