1681986653 has 2 divisors, whose sum is σ = 1681986654. Its totient is φ = 1681986652.

The previous prime is 1681986637. The next prime is 1681986661. The reversal of 1681986653 is 3566891861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1681164004 + 822649 = 41002^2 + 907^2 .

It is a cyclic number.

It is not a de Polignac number, because 1681986653 - 2⁴ = 1681986637 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1681986595 and 1681986604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1681986673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840993326 + 840993327.

It is an arithmetic number, because the mean of its divisors is an integer number (840993327).

Almost surely, 2^1681986653 is an apocalyptic number.

It is an amenable number.

1681986653 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681986653 is an equidigital number, since it uses as much as digits as its factorization.

1681986653 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1866240, while the sum is 53.

The square root of 1681986653 is about 41012.0305885968. The cubic root of 1681986653 is about 1189.2527976474.

The spelling of 1681986653 in words is "one billion, six hundred eighty-one million, nine hundred eighty-six thousand, six hundred fifty-three".