1216540423 has 6 divisors (see below), whose sum is σ = 1390437384. Its totient is φ = 1042669836.

The previous prime is 1216540421. The next prime is 1216540441. The reversal of 1216540423 is 3240456121.

It is not a de Polignac number, because 1216540423 - 2¹ = 1216540421 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1216540391 and 1216540400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216540421) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 85690 + ... + 98872.

It is an arithmetic number, because the mean of its divisors is an integer number (231739564).

Almost surely, 2^1216540423 is an apocalyptic number.

1216540423 is a deficient number, since it is larger than the sum of its proper divisors (173896961).

1216540423 is an frugal number, since it uses more digits than its factorization.

1216540423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26373 (or 13190 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 1216540423 is about 34878.9395337645. The cubic root of 1216540423 is about 1067.5187573008.

Multiplying 1216540423 by its sum of digits (28), we get a square (34063131844 = 184562²).

Adding to 1216540423 its reverse (3240456121), we get a palindrome (4456996544).

The spelling of 1216540423 in words is "one billion, two hundred sixteen million, five hundred forty thousand, four hundred twenty-three".