1388829948661 has 4 divisors (see below), whose sum is σ = 1470525828012. Its totient is φ = 1307134069312.

The previous prime is 1388829948643. The next prime is 1388829948673. The reversal of 1388829948661 is 1668499288831.

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 1022108868036 + 366721080625 = 1010994^2 + 605575^2 .

It is a cyclic number.

It is not a de Polignac number, because 1388829948661 - 2²⁹ = 1388293077749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1388829948761) 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, 40847939650 + ... + 40847939683.

It is an arithmetic number, because the mean of its divisors is an integer number (367631457003).

Almost surely, 2^{1388829948661} is an apocalyptic number.

It is an amenable number.

1388829948661 is a deficient number, since it is larger than the sum of its proper divisors (81695879351).

1388829948661 is an equidigital number, since it uses as much as digits as its factorization.

1388829948661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81695879350.

The product of its digits is 286654464, while the sum is 73.

The spelling of 1388829948661 in words is "one trillion, three hundred eighty-eight billion, eight hundred twenty-nine million, nine hundred forty-eight thousand, six hundred sixty-one".