1990401871 has 8 divisors (see below), whose sum is σ = 2108438640. Its totient is φ = 1872471168.

The previous prime is 1990401851. The next prime is 1990401901. The reversal of 1990401871 is 1781040991.

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 1990401871 - 2⁹ = 1990401359 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 (1990401851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13900 + ... + 64606.

It is an arithmetic number, because the mean of its divisors is an integer number (263554830).

Almost surely, 2^1990401871 is an apocalyptic number.

1990401871 is a deficient number, since it is larger than the sum of its proper divisors (118036769).

1990401871 is a wasteful number, since it uses less digits than its factorization.

1990401871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53033.

The product of its (nonzero) digits is 18144, while the sum is 40.

The square root of 1990401871 is about 44613.9201483125. The cubic root of 1990401871 is about 1257.9023363360.

The spelling of 1990401871 in words is "one billion, nine hundred ninety million, four hundred one thousand, eight hundred seventy-one".