1023123021155 has 4 divisors (see below), whose sum is σ = 1227747625392. Its totient is φ = 818498416920.

The previous prime is 1023123021149. The next prime is 1023123021157. The reversal of 1023123021155 is 5511203213201.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1023123021155 - 2⁴ = 1023123021139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1023123021157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102312302111 + ... + 102312302120.

It is an arithmetic number, because the mean of its divisors is an integer number (306936906348).

Almost surely, 2^{1023123021155} is an apocalyptic number.

1023123021155 is a deficient number, since it is larger than the sum of its proper divisors (204624604237).

1023123021155 is an equidigital number, since it uses as much as digits as its factorization.

1023123021155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204624604236.

The product of its (nonzero) digits is 1800, while the sum is 26.

Adding to 1023123021155 its reverse (5511203213201), we get a palindrome (6534326234356).

The spelling of 1023123021155 in words is "one trillion, twenty-three billion, one hundred twenty-three million, twenty-one thousand, one hundred fifty-five".