1688572681 has 2 divisors, whose sum is σ = 1688572682. Its totient is φ = 1688572680.

The previous prime is 1688572679. The next prime is 1688572687. The reversal of 1688572681 is 1862758861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1688470281 + 102400 = 41091^2 + 320^2 .

It is an emirp because it is prime and its reverse (1862758861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1688572681 - 2¹ = 1688572679 is a prime.

It is a super-2 number, since 2×1688572681² = 5702555398039055522, which contains 22 as substring.

Together with 1688572679, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1688572687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 844286340 + 844286341.

It is an arithmetic number, because the mean of its divisors is an integer number (844286341).

Almost surely, 2^1688572681 is an apocalyptic number.

It is an amenable number.

1688572681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1688572681 is an equidigital number, since it uses as much as digits as its factorization.

1688572681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1290240, while the sum is 52.

The square root of 1688572681 is about 41092.2459960514. The cubic root of 1688572681 is about 1190.8029984989.

The spelling of 1688572681 in words is "one billion, six hundred eighty-eight million, five hundred seventy-two thousand, six hundred eighty-one".