1646443964 has 12 divisors (see below), whose sum is σ = 3143211288. Its totient is φ = 748383600.

The previous prime is 1646443961. The next prime is 1646443973. The reversal of 1646443964 is 4693446461.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1646443961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18709547 + ... + 18709634.

It is an arithmetic number, because the mean of its divisors is an integer number (261934274).

Almost surely, 2^1646443964 is an apocalyptic number.

It is an amenable number.

1646443964 is a deficient number, since it is larger than the sum of its proper divisors (1496767324).

1646443964 is a wasteful number, since it uses less digits than its factorization.

1646443964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37419196 (or 37419194 counting only the distinct ones).

The product of its digits is 1492992, while the sum is 47.

The square root of 1646443964 is about 40576.3966364683. The cubic root of 1646443964 is about 1180.8162417239.

The spelling of 1646443964 in words is "one billion, six hundred forty-six million, four hundred forty-three thousand, nine hundred sixty-four".