1646331421 has 32 divisors (see below), whose sum is σ = 2069660160. Its totient is φ = 1278461184.

The previous prime is 1646331409. The next prime is 1646331431. The reversal of 1646331421 is 1241336461.

It is a happy number.

It is not a de Polignac number, because 1646331421 - 2⁵ = 1646331389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1646331431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 244131 + ... + 250783.

It is an arithmetic number, because the mean of its divisors is an integer number (64676880).

Almost surely, 2^1646331421 is an apocalyptic number.

It is an amenable number.

1646331421 is a deficient number, since it is larger than the sum of its proper divisors (423328739).

1646331421 is a wasteful number, since it uses less digits than its factorization.

1646331421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6765.

The product of its digits is 10368, while the sum is 31.

The square root of 1646331421 is about 40575.0098089945. The cubic root of 1646331421 is about 1180.7893361356.

Adding to 1646331421 its reverse (1241336461), we get a palindrome (2887667882).

The spelling of 1646331421 in words is "one billion, six hundred forty-six million, three hundred thirty-one thousand, four hundred twenty-one".