1216865023 has 4 divisors (see below), whose sum is σ = 1327489128. Its totient is φ = 1106240920.

The previous prime is 1216865017. The next prime is 1216865033. The reversal of 1216865023 is 3205686121.

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 1216865023 - 2¹³ = 1216856831 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1216865023.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216865033) 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, 55312036 + ... + 55312057.

It is an arithmetic number, because the mean of its divisors is an integer number (331872282).

Almost surely, 2^1216865023 is an apocalyptic number.

1216865023 is a deficient number, since it is larger than the sum of its proper divisors (110624105).

1216865023 is a wasteful number, since it uses less digits than its factorization.

1216865023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110624104.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 1216865023 is about 34883.5924612131. The cubic root of 1216865023 is about 1067.6136947610.

The spelling of 1216865023 in words is "one billion, two hundred sixteen million, eight hundred sixty-five thousand, twenty-three".