1681689253 has 2 divisors, whose sum is σ = 1681689254. Its totient is φ = 1681689252.

The previous prime is 1681689227. The next prime is 1681689263. The reversal of 1681689253 is 3529861861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1607849604 + 73839649 = 40098^2 + 8593^2 .

It is a cyclic number.

It is not a de Polignac number, because 1681689253 - 2¹³ = 1681681061 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1681689197 and 1681689206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1681689203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840844626 + 840844627.

It is an arithmetic number, because the mean of its divisors is an integer number (840844627).

Almost surely, 2^1681689253 is an apocalyptic number.

It is an amenable number.

1681689253 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681689253 is an equidigital number, since it uses as much as digits as its factorization.

1681689253 is an evil number, because the sum of its binary digits is even.

The product of its digits is 622080, while the sum is 49.

The square root of 1681689253 is about 41008.4046629468. The cubic root of 1681689253 is about 1189.1827010489.

The spelling of 1681689253 in words is "one billion, six hundred eighty-one million, six hundred eighty-nine thousand, two hundred fifty-three".