1921065646 has 4 divisors (see below), whose sum is σ = 2881598472. Its totient is φ = 960532822.

The previous prime is 1921065631. The next prime is 1921065683. The reversal of 1921065646 is 6465601291.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 1921065599 and 1921065608.

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 as a sum of consecutive naturals, namely, 480266410 + ... + 480266413.

It is an arithmetic number, because the mean of its divisors is an integer number (720399618).

Almost surely, 2^1921065646 is an apocalyptic number.

1921065646 is a deficient number, since it is larger than the sum of its proper divisors (960532826).

1921065646 is an equidigital number, since it uses as much as digits as its factorization.

1921065646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 960532825.

The product of its (nonzero) digits is 77760, while the sum is 40.

The square root of 1921065646 is about 43829.9628792907. The cubic root of 1921065646 is about 1243.1229049843.

The spelling of 1921065646 in words is "one billion, nine hundred twenty-one million, sixty-five thousand, six hundred forty-six".