1223197987 has 4 divisors (see below), whose sum is σ = 1334397816. Its totient is φ = 1111998160.

The previous prime is 1223197981. The next prime is 1223198021. The reversal of 1223197987 is 7897913221.

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-1223197987 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 1223197987.

It is not an unprimeable number, because it can be changed into a prime (1223197981) 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, 55599898 + ... + 55599919.

It is an arithmetic number, because the mean of its divisors is an integer number (333599454).

Almost surely, 2^1223197987 is an apocalyptic number.

1223197987 is a deficient number, since it is larger than the sum of its proper divisors (111199829).

1223197987 is a wasteful number, since it uses less digits than its factorization.

1223197987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111199828.

The product of its digits is 381024, while the sum is 49.

The square root of 1223197987 is about 34974.2474829695. The cubic root of 1223197987 is about 1069.4625614983.

The spelling of 1223197987 in words is "one billion, two hundred twenty-three million, one hundred ninety-seven thousand, nine hundred eighty-seven".