1990654 has 4 divisors (see below), whose sum is σ = 2985984. Its totient is φ = 995326.

The previous prime is 1990643. The next prime is 1990657. The reversal of 1990654 is 4560991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 4560991 = 853 ⋅5347.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 497662 + ... + 497665.

It is an arithmetic number, because the mean of its divisors is an integer number (746496).

2^1990654 is an apocalyptic number.

1990654 is a deficient number, since it is larger than the sum of its proper divisors (995330).

1990654 is an equidigital number, since it uses as much as digits as its factorization.

1990654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 995329.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 1990654 is about 1410.9053830785. The cubic root of 1990654 is about 125.7955447933.

The spelling of 1990654 in words is "one million, nine hundred ninety thousand, six hundred fifty-four".