1221023100123 has 12 divisors (see below), whose sum is σ = 1769371098768. Its totient is φ = 811397985360.

The previous prime is 1221023100103. The next prime is 1221023100137. The reversal of 1221023100123 is 3210013201221.

It is not a de Polignac number, because 1221023100123 - 2¹⁰ = 1221023099099 is a prime.

It is a super-2 number, since 2×1221023100123² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221023100096 and 1221023100105.

It is not an unprimeable number, because it can be changed into a prime (1221023100103) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 218114940 + ... + 218120537.

It is an arithmetic number, because the mean of its divisors is an integer number (147447591564).

Almost surely, 2^{1221023100123} is an apocalyptic number.

1221023100123 is a deficient number, since it is larger than the sum of its proper divisors (548347998645).

1221023100123 is a wasteful number, since it uses less digits than its factorization.

1221023100123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436235794 (or 436235791 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 1221023100123 its reverse (3210013201221), we get a palindrome (4431036301344).

The spelling of 1221023100123 in words is "one trillion, two hundred twenty-one billion, twenty-three million, one hundred thousand, one hundred twenty-three".