680687881 has 2 divisors, whose sum is σ = 680687882. Its totient is φ = 680687880.

The previous prime is 680687879. The next prime is 680687933. The reversal of 680687881 is 188786086.

It is an a-pointer prime, because the next prime (680687933) can be obtained adding 680687881 to its sum of digits (52).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 544755600 + 135932281 = 23340^2 + 11659^2 .

It is a cyclic number.

It is not a de Polignac number, because 680687881 - 2¹ = 680687879 is a prime.

It is a super-2 number, since 2×680687881² = 926671982680540322, which contains 22 as substring.

Together with 680687879, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (680687081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340343940 + 340343941.

It is an arithmetic number, because the mean of its divisors is an integer number (340343941).

Almost surely, 2^680687881 is an apocalyptic number.

It is an amenable number.

680687881 is a deficient number, since it is larger than the sum of its proper divisors (1).

680687881 is an equidigital number, since it uses as much as digits as its factorization.

680687881 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1032192, while the sum is 52.

The square root of 680687881 is about 26089.9958029893. The cubic root of 680687881 is about 879.6623536782.

The spelling of 680687881 in words is "six hundred eighty million, six hundred eighty-seven thousand, eight hundred eighty-one".