155241312421 has 4 divisors (see below), whose sum is σ = 167182951852. Its totient is φ = 143299672992.

The previous prime is 155241312407. The next prime is 155241312437. The reversal of 155241312421 is 124213142551.

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 77862763521 + 77378548900 = 279039^2 + 278170^2 .

It is a cyclic number.

It is not a de Polignac number, because 155241312421 - 2¹¹ = 155241310373 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 (155241312461) 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, 5970819696 + ... + 5970819721.

It is an arithmetic number, because the mean of its divisors is an integer number (41795737963).

Almost surely, 2^155241312421 is an apocalyptic number.

It is an amenable number.

155241312421 is a deficient number, since it is larger than the sum of its proper divisors (11941639431).

155241312421 is a wasteful number, since it uses less digits than its factorization.

155241312421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11941639430.

The product of its digits is 9600, while the sum is 31.

Adding to 155241312421 its reverse (124213142551), we get a palindrome (279454454972).

The spelling of 155241312421 in words is "one hundred fifty-five billion, two hundred forty-one million, three hundred twelve thousand, four hundred twenty-one".