1242647986 has 4 divisors (see below), whose sum is σ = 1863971982. Its totient is φ = 621323992.

The previous prime is 1242647983. The next prime is 1242648037. The reversal of 1242647986 is 6897462421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6897462421 = 39181 ⋅176041.

It can be written as a sum of positive squares in only one way, i.e., 1241505225 + 1142761 = 35235^2 + 1069^2 .

It is not an unprimeable number, because it can be changed into a prime (1242647983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310661995 + ... + 310661998.

Almost surely, 2^1242647986 is an apocalyptic number.

1242647986 is a deficient number, since it is larger than the sum of its proper divisors (621323996).

1242647986 is an equidigital number, since it uses as much as digits as its factorization.

1242647986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 621323995.

The product of its digits is 1161216, while the sum is 49.

The square root of 1242647986 is about 35251.2125465210. The cubic root of 1242647986 is about 1075.1012663932.

The spelling of 1242647986 in words is "one billion, two hundred forty-two million, six hundred forty-seven thousand, nine hundred eighty-six".