1247977109 has 4 divisors (see below), whose sum is σ = 1260333420. Its totient is φ = 1235620800.

The previous prime is 1247977103. The next prime is 1247977111. The reversal of 1247977109 is 9017797421.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 747202225 + 500774884 = 27335^2 + 22378^2 .

It is a cyclic number.

It is not a de Polignac number, because 1247977109 - 2¹⁶ = 1247911573 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1247977103) 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, 6178004 + ... + 6178205.

It is an arithmetic number, because the mean of its divisors is an integer number (315083355).

Almost surely, 2^1247977109 is an apocalyptic number.

It is an amenable number.

1247977109 is a deficient number, since it is larger than the sum of its proper divisors (12356311).

1247977109 is a wasteful number, since it uses less digits than its factorization.

1247977109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12356310.

The product of its (nonzero) digits is 222264, while the sum is 47.

The square root of 1247977109 is about 35326.7194769059. The cubic root of 1247977109 is about 1076.6359397319.

The spelling of 1247977109 in words is "one billion, two hundred forty-seven million, nine hundred seventy-seven thousand, one hundred nine".