155210243234021 has 4 divisors (see below), whose sum is σ = 155555923063500. Its totient is φ = 154864563404544.

The previous prime is 155210243234003. The next prime is 155210243234029. The reversal of 155210243234021 is 120432342012551.

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 133153459737796 + 22056783496225 = 11539214^2 + 4696465^2 .

It is a cyclic number.

It is not a de Polignac number, because 155210243234021 - 2¹⁰ = 155210243232997 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 (155210243234029) 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, 172839914066 + ... + 172839914963.

It is an arithmetic number, because the mean of its divisors is an integer number (38888980765875).

Almost surely, 2^{155210243234021} is an apocalyptic number.

It is an amenable number.

155210243234021 is a deficient number, since it is larger than the sum of its proper divisors (345679829479).

155210243234021 is an equidigital number, since it uses as much as digits as its factorization.

155210243234021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345679829478.

The product of its (nonzero) digits is 57600, while the sum is 35.

Adding to 155210243234021 its reverse (120432342012551), we get a palindrome (275642585246572).

The spelling of 155210243234021 in words is "one hundred fifty-five trillion, two hundred ten billion, two hundred forty-three million, two hundred thirty-four thousand, twenty-one".