1671206681 has 2 divisors, whose sum is σ = 1671206682. Its totient is φ = 1671206680.

The previous prime is 1671206633. The next prime is 1671206687. The reversal of 1671206681 is 1866021761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1512043225 + 159163456 = 38885^2 + 12616^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1671206681 is a prime.

It is a super-2 number, since 2×1671206681² = 5585863541238071522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1671206687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 835603340 + 835603341.

It is an arithmetic number, because the mean of its divisors is an integer number (835603341).

Almost surely, 2^1671206681 is an apocalyptic number.

It is an amenable number.

1671206681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1671206681 is an equidigital number, since it uses as much as digits as its factorization.

1671206681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 1671206681 is about 40880.3948244143. The cubic root of 1671206681 is about 1186.7066818960.

The spelling of 1671206681 in words is "one billion, six hundred seventy-one million, two hundred six thousand, six hundred eighty-one".