1661314749857 has 8 divisors (see below), whose sum is σ = 1898850076032. Its totient is φ = 1423830585600.

The previous prime is 1661314749841. The next prime is 1661314749889. The reversal of 1661314749857 is 7589474131661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1661314749857 - 2⁴ = 1661314749841 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1661314749857.

It is not an unprimeable number, because it can be changed into a prime (1661314743857) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12720869 + ... + 12850802.

It is an arithmetic number, because the mean of its divisors is an integer number (237356259504).

Almost surely, 2^{1661314749857} is an apocalyptic number.

It is an amenable number.

1661314749857 is a deficient number, since it is larger than the sum of its proper divisors (237535326175).

1661314749857 is an equidigital number, since it uses as much as digits as its factorization.

1661314749857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25580959.

The product of its digits is 30481920, while the sum is 62.

The spelling of 1661314749857 in words is "one trillion, six hundred sixty-one billion, three hundred fourteen million, seven hundred forty-nine thousand, eight hundred fifty-seven".