1216487973 has 4 divisors (see below), whose sum is σ = 1621983968. Its totient is φ = 810991980.

The previous prime is 1216487971. The next prime is 1216487983. The reversal of 1216487973 is 3797846121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1216487973 - 2¹ = 1216487971 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216487971) 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, 202747993 + ... + 202747998.

It is an arithmetic number, because the mean of its divisors is an integer number (405495992).

Almost surely, 2^1216487973 is an apocalyptic number.

It is an amenable number.

1216487973 is a deficient number, since it is larger than the sum of its proper divisors (405495995).

1216487973 is an equidigital number, since it uses as much as digits as its factorization.

1216487973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405495994.

The product of its digits is 508032, while the sum is 48.

The square root of 1216487973 is about 34878.1876392682. The cubic root of 1216487973 is about 1067.5034153902.

The spelling of 1216487973 in words is "one billion, two hundred sixteen million, four hundred eighty-seven thousand, nine hundred seventy-three".