1291685052802 has 4 divisors (see below), whose sum is σ = 1937527579206. Its totient is φ = 645842526400.

The previous prime is 1291685052797. The next prime is 1291685052811. The reversal of 1291685052802 is 2082505861921.

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

It can be written as a sum of positive squares in only one way, i.e., 1285073899321 + 6611153481 = 1133611^2 + 81309^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322921263199 + ... + 322921263202.

Almost surely, 2^{1291685052802} is an apocalyptic number.

1291685052802 is a deficient number, since it is larger than the sum of its proper divisors (645842526404).

1291685052802 is an equidigital number, since it uses as much as digits as its factorization.

1291685052802 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645842526403.

The product of its (nonzero) digits is 691200, while the sum is 49.

The spelling of 1291685052802 in words is "one trillion, two hundred ninety-one billion, six hundred eighty-five million, fifty-two thousand, eight hundred two".