1646938861 has 2 divisors, whose sum is σ = 1646938862. Its totient is φ = 1646938860.

The previous prime is 1646938849. The next prime is 1646938873. The reversal of 1646938861 is 1688396461.

It is a balanced prime because it is at equal distance from previous prime (1646938849) and next prime (1646938873).

It can be written as a sum of positive squares in only one way, i.e., 1509322500 + 137616361 = 38850^2 + 11731^2 .

It is a cyclic number.

It is not a de Polignac number, because 1646938861 - 2¹¹ = 1646936813 is a prime.

It is a super-2 number, since 2×1646938861² = 5424815223743954642, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1646938799 and 1646938808.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1646938261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 823469430 + 823469431.

It is an arithmetic number, because the mean of its divisors is an integer number (823469431).

Almost surely, 2^1646938861 is an apocalyptic number.

It is an amenable number.

1646938861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1646938861 is an equidigital number, since it uses as much as digits as its factorization.

1646938861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1492992, while the sum is 52.

The square root of 1646938861 is about 40582.4945142607. The cubic root of 1646938861 is about 1180.9345419082.

The spelling of 1646938861 in words is "one billion, six hundred forty-six million, nine hundred thirty-eight thousand, eight hundred sixty-one".