681138001 has 2 divisors, whose sum is σ = 681138002. Its totient is φ = 681138000.

The previous prime is 681137981. The next prime is 681138071. The reversal of 681138001 is 100831186.

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., 448422976 + 232715025 = 21176^2 + 15255^2 .

It is a cyclic number.

It is not a de Polignac number, because 681138001 - 2¹⁷ = 681006929 is a prime.

It is not a weakly prime, because it can be changed into another prime (681138071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340569000 + 340569001.

It is an arithmetic number, because the mean of its divisors is an integer number (340569001).

Almost surely, 2^681138001 is an apocalyptic number.

It is an amenable number.

681138001 is a deficient number, since it is larger than the sum of its proper divisors (1).

681138001 is an equidigital number, since it uses as much as digits as its factorization.

681138001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 681138001 is about 26098.6206723650. The cubic root of 681138001 is about 879.8562097190.

Adding to 681138001 its reverse (100831186), we get a palindrome (781969187).

The spelling of 681138001 in words is "six hundred eighty-one million, one hundred thirty-eight thousand, one".