1649821894 has 16 divisors (see below), whose sum is σ = 2840007456. Its totient is φ = 704131200.

The previous prime is 1649821879. The next prime is 1649821909. The reversal of 1649821894 is 4981289461.

It is an interprime number because it is at equal distance from previous prime (1649821879) and next prime (1649821909).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 241117 + ... + 247864.

It is an arithmetic number, because the mean of its divisors is an integer number (177500466).

Almost surely, 2^1649821894 is an apocalyptic number.

1649821894 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

1649821894 is a deficient number, since it is larger than the sum of its proper divisors (1190185562).

1649821894 is a wasteful number, since it uses less digits than its factorization.

1649821894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 489231.

The product of its digits is 995328, while the sum is 52.

The square root of 1649821894 is about 40617.9996307056. Note that the first 3 decimals coincide. The cubic root of 1649821894 is about 1181.6232314103.

It can be divided in two parts, 1649 and 821894, that added together give a 7-th power (823543 = 7⁷).

The spelling of 1649821894 in words is "one billion, six hundred forty-nine million, eight hundred twenty-one thousand, eight hundred ninety-four".