1221210023123 has 4 divisors (see below), whose sum is σ = 1228522658160. Its totient is φ = 1213897388088.

The previous prime is 1221210023119. The next prime is 1221210023153. The reversal of 1221210023123 is 3213200121221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221210023123 - 2² = 1221210023119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221210023095 and 1221210023104.

It is not an unprimeable number, because it can be changed into a prime (1221210023153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3656317268 + ... + 3656317601.

It is an arithmetic number, because the mean of its divisors is an integer number (307130664540).

Almost surely, 2^{1221210023123} is an apocalyptic number.

1221210023123 is a deficient number, since it is larger than the sum of its proper divisors (7312635037).

1221210023123 is an equidigital number, since it uses as much as digits as its factorization.

1221210023123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7312635036.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 1221210023123 its reverse (3213200121221), we get a palindrome (4434410144344).

The spelling of 1221210023123 in words is "one trillion, two hundred twenty-one billion, two hundred ten million, twenty-three thousand, one hundred twenty-three".