1291369949 has 4 divisors (see below), whose sum is σ = 1291444380. Its totient is φ = 1291295520.

The previous prime is 1291369943. The next prime is 1291369957. The reversal of 1291369949 is 9499631921.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 9499631921 = 13 ⋅730740917.

It can be written as a sum of positive squares in 2 ways, for example, as 581147449 + 710222500 = 24107^2 + 26650^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1291369949 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 1291369949.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291369943) 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, 4097 + ... + 50985.

It is an arithmetic number, because the mean of its divisors is an integer number (322861095).

Almost surely, 2^1291369949 is an apocalyptic number.

It is an amenable number.

1291369949 is a deficient number, since it is larger than the sum of its proper divisors (74431).

1291369949 is an equidigital number, since it uses as much as digits as its factorization.

1291369949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74430.

The product of its digits is 944784, while the sum is 53.

The square root of 1291369949 is about 35935.6361986260. The cubic root of 1291369949 is about 1088.9724482828.

The spelling of 1291369949 in words is "one billion, two hundred ninety-one million, three hundred sixty-nine thousand, nine hundred forty-nine".