1990497571 has 2 divisors, whose sum is σ = 1990497572. Its totient is φ = 1990497570.

The previous prime is 1990497559. The next prime is 1990497637. The reversal of 1990497571 is 1757940991.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1990497571 is a prime.

It is not a weakly prime, because it can be changed into another prime (1990492571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 995248785 + 995248786.

It is an arithmetic number, because the mean of its divisors is an integer number (995248786).

Almost surely, 2^1990497571 is an apocalyptic number.

1990497571 is a deficient number, since it is larger than the sum of its proper divisors (1).

1990497571 is an equidigital number, since it uses as much as digits as its factorization.

1990497571 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 714420, while the sum is 52.

The square root of 1990497571 is about 44614.9926706259. The cubic root of 1990497571 is about 1257.9224963057.

The spelling of 1990497571 in words is "one billion, nine hundred ninety million, four hundred ninety-seven thousand, five hundred seventy-one".