1213511423 has 4 divisors (see below), whose sum is σ = 1220216088. Its totient is φ = 1206806760.

The previous prime is 1213511401. The next prime is 1213511447. The reversal of 1213511423 is 3241153121.

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 1213511423 - 2²⁰ = 1212462847 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 (1213511483) 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, 3352061 + ... + 3352422.

It is an arithmetic number, because the mean of its divisors is an integer number (305054022).

Almost surely, 2^1213511423 is an apocalyptic number.

1213511423 is a deficient number, since it is larger than the sum of its proper divisors (6704665).

1213511423 is an equidigital number, since it uses as much as digits as its factorization.

1213511423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6704664.

The product of its digits is 720, while the sum is 23.

The square root of 1213511423 is about 34835.4908534385. The cubic root of 1213511423 is about 1066.6320346937.

Adding to 1213511423 its reverse (3241153121), we get a palindrome (4454664544).

The spelling of 1213511423 in words is "one billion, two hundred thirteen million, five hundred eleven thousand, four hundred twenty-three".