1242837649817 has 4 divisors (see below), whose sum is σ = 1246758273636. Its totient is φ = 1238917026000.

The previous prime is 1242837649813. The next prime is 1242837649841. The reversal of 1242837649817 is 7189467382421.

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 343420612441 + 899417037376 = 586021^2 + 948376^2 .

It is a cyclic number.

It is not a de Polignac number, because 1242837649817 - 2² = 1242837649813 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 1242837649817.

It is not an unprimeable number, because it can be changed into a prime (1242837649813) 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, 1960311434 + ... + 1960312067.

It is an arithmetic number, because the mean of its divisors is an integer number (311689568409).

Almost surely, 2^{1242837649817} is an apocalyptic number.

It is an amenable number.

1242837649817 is a deficient number, since it is larger than the sum of its proper divisors (3920623819).

1242837649817 is an equidigital number, since it uses as much as digits as its factorization.

1242837649817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3920623818.

The product of its digits is 32514048, while the sum is 62.

The spelling of 1242837649817 in words is "one trillion, two hundred forty-two billion, eight hundred thirty-seven million, six hundred forty-nine thousand, eight hundred seventeen".