1990649 has 8 divisors (see below), whose sum is σ = 2219040. Its totient is φ = 1774656.

The previous prime is 1990643. The next prime is 1990657. The reversal of 1990649 is 9460991.

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 1990649 - 2¹² = 1986553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1990643) 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, 2759 + ... + 3404.

It is an arithmetic number, because the mean of its divisors is an integer number (277380).

2^1990649 is an apocalyptic number.

1990649 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1990649 is a deficient number, since it is larger than the sum of its proper divisors (228391).

1990649 is a wasteful number, since it uses less digits than its factorization.

1990649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6199.

The product of its (nonzero) digits is 17496, while the sum is 38.

The square root of 1990649 is about 1410.9036111656. The cubic root of 1990649 is about 125.7954394714.

The spelling of 1990649 in words is "one million, nine hundred ninety thousand, six hundred forty-nine".