1646394971 has 16 divisors (see below), whose sum is σ = 1893979584. Its totient is φ = 1417672704.

The previous prime is 1646394961. The next prime is 1646394977. The reversal of 1646394971 is 1794936461.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-1646394971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1646394977) 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 in 15 ways as a sum of consecutive naturals, for example, 7991 + ... + 57936.

It is an arithmetic number, because the mean of its divisors is an integer number (118373724).

Almost surely, 2^1646394971 is an apocalyptic number.

1646394971 is a deficient number, since it is larger than the sum of its proper divisors (247584613).

1646394971 is a wasteful number, since it uses less digits than its factorization.

1646394971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66070.

The product of its digits is 979776, while the sum is 50.

The square root of 1646394971 is about 40575.7929189314. The cubic root of 1646394971 is about 1180.8045291472.

The spelling of 1646394971 in words is "one billion, six hundred forty-six million, three hundred ninety-four thousand, nine hundred seventy-one".