1221153151423 has 4 divisors (see below), whose sum is σ = 1292985689760. Its totient is φ = 1149320613088.

The previous prime is 1221153151397. The next prime is 1221153151429. The reversal of 1221153151423 is 3241513511221.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221153151423 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 (1221153151429) 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, 35916269143 + ... + 35916269176.

It is an arithmetic number, because the mean of its divisors is an integer number (323246422440).

Almost surely, 2^{1221153151423} is an apocalyptic number.

1221153151423 is a deficient number, since it is larger than the sum of its proper divisors (71832538337).

1221153151423 is an equidigital number, since it uses as much as digits as its factorization.

1221153151423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71832538336.

The product of its digits is 7200, while the sum is 31.

Adding to 1221153151423 its reverse (3241513511221), we get a palindrome (4462666662644).

The spelling of 1221153151423 in words is "one trillion, two hundred twenty-one billion, one hundred fifty-three million, one hundred fifty-one thousand, four hundred twenty-three".