681627769 has 2 divisors, whose sum is σ = 681627770. Its totient is φ = 681627768.

The previous prime is 681627757. The next prime is 681627797. The reversal of 681627769 is 967726186.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 511664400 + 169963369 = 22620^2 + 13037^2 .

It is a cyclic number.

It is not a de Polignac number, because 681627769 - 2¹⁵ = 681595001 is a prime.

It is a super-2 number, since 2×681627769² = 929232830943834722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (681627799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340813884 + 340813885.

It is an arithmetic number, because the mean of its divisors is an integer number (340813885).

Almost surely, 2^681627769 is an apocalyptic number.

It is an amenable number.

681627769 is a deficient number, since it is larger than the sum of its proper divisors (1).

681627769 is an equidigital number, since it uses as much as digits as its factorization.

681627769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1524096, while the sum is 52.

The square root of 681627769 is about 26108.0020108778. The cubic root of 681627769 is about 880.0670442205.

The spelling of 681627769 in words is "six hundred eighty-one million, six hundred twenty-seven thousand, seven hundred sixty-nine".