1990942342657 has 8 divisors (see below), whose sum is σ = 1996200529920. Its totient is φ = 1985684468160.

The previous prime is 1990942342579. The next prime is 1990942342799. The reversal of 1990942342657 is 7562432490991.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1990942342657 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1990942342595 and 1990942342604.

It is not an unprimeable number, because it can be changed into a prime (1990942342357) 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, 18421657 + ... + 18529417.

It is an arithmetic number, because the mean of its divisors is an integer number (249525066240).

Almost surely, 2^{1990942342657} is an apocalyptic number.

It is an amenable number.

1990942342657 is a deficient number, since it is larger than the sum of its proper divisors (5258187263).

1990942342657 is a wasteful number, since it uses less digits than its factorization.

1990942342657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156383.

The product of its (nonzero) digits is 29393280, while the sum is 61.

The spelling of 1990942342657 in words is "one trillion, nine hundred ninety billion, nine hundred forty-two million, three hundred forty-two thousand, six hundred fifty-seven".