1247889361 has 4 divisors (see below), whose sum is σ = 1248499252. Its totient is φ = 1247279472.

The previous prime is 1247889337. The next prime is 1247889413. The reversal of 1247889361 is 1639887421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1639887421 = 19009 ⋅86269.

It can be written as a sum of positive squares in 2 ways, for example, as 321843600 + 926045761 = 17940^2 + 30431^2 .

It is a cyclic number.

It is not a de Polignac number, because 1247889361 - 2⁵ = 1247889329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1247289361) 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, 301866 + ... + 305971.

It is an arithmetic number, because the mean of its divisors is an integer number (312124813).

Almost surely, 2^1247889361 is an apocalyptic number.

It is an amenable number.

1247889361 is a deficient number, since it is larger than the sum of its proper divisors (609891).

1247889361 is an equidigital number, since it uses as much as digits as its factorization.

1247889361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 609890.

The product of its digits is 580608, while the sum is 49.

The square root of 1247889361 is about 35325.4775056191. The cubic root of 1247889361 is about 1076.6107055979.

The spelling of 1247889361 in words is "one billion, two hundred forty-seven million, eight hundred eighty-nine thousand, three hundred sixty-one".