1243320136 has 8 divisors (see below), whose sum is σ = 2331225270. Its totient is φ = 621660064.

The previous prime is 1243320079. The next prime is 1243320151. The reversal of 1243320136 is 6310233421.

It can be written as a sum of positive squares in only one way, i.e., 1182947236 + 60372900 = 34394^2 + 7770^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 1243320136.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77707501 + ... + 77707516.

Almost surely, 2^1243320136 is an apocalyptic number.

It is an amenable number.

1243320136 is a deficient number, since it is larger than the sum of its proper divisors (1087905134).

1243320136 is a wasteful number, since it uses less digits than its factorization.

1243320136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155415023 (or 155415019 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 1243320136 is about 35260.7449722776. The cubic root of 1243320136 is about 1075.2950727039.

Adding to 1243320136 its reverse (6310233421), we get a palindrome (7553553557).

The spelling of 1243320136 in words is "one billion, two hundred forty-three million, three hundred twenty thousand, one hundred thirty-six".