1221153423 has 16 divisors (see below), whose sum is σ = 1866685440. Its totient is φ = 695596896.

The previous prime is 1221153419. The next prime is 1221153433. The reversal of 1221153423 is 3243511221.

It is not a de Polignac number, because 1221153423 - 2² = 1221153419 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221153393 and 1221153402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221153413) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85063 + ... + 98376.

It is an arithmetic number, because the mean of its divisors is an integer number (116667840).

Almost surely, 2^1221153423 is an apocalyptic number.

1221153423 is a deficient number, since it is larger than the sum of its proper divisors (645532017).

1221153423 is a wasteful number, since it uses less digits than its factorization.

1221153423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183766.

The product of its digits is 1440, while the sum is 24.

The square root of 1221153423 is about 34945.0056946626. The cubic root of 1221153423 is about 1068.8663636373.

Adding to 1221153423 its reverse (3243511221), we get a palindrome (4464664644).

The spelling of 1221153423 in words is "one billion, two hundred twenty-one million, one hundred fifty-three thousand, four hundred twenty-three".