155031122342021 has 4 divisors (see below), whose sum is σ = 155031193346700. Its totient is φ = 155031051337344.

The previous prime is 155031122342003. The next prime is 155031122342051. The reversal of 155031122342021 is 120243221130551.

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 38328171450625 + 116702950891396 = 6190975^2 + 10802914^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155031122342021 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 (155031122342051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32119826 + ... + 36629843.

It is an arithmetic number, because the mean of its divisors is an integer number (38757798336675).

Almost surely, 2^{155031122342021} is an apocalyptic number.

It is an amenable number.

155031122342021 is a deficient number, since it is larger than the sum of its proper divisors (71004679).

155031122342021 is an equidigital number, since it uses as much as digits as its factorization.

155031122342021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71004678.

The product of its (nonzero) digits is 14400, while the sum is 32.

Adding to 155031122342021 its reverse (120243221130551), we get a palindrome (275274343472572).

The spelling of 155031122342021 in words is "one hundred fifty-five trillion, thirty-one billion, one hundred twenty-two million, three hundred forty-two thousand, twenty-one".