687131707 has 2 divisors, whose sum is σ = 687131708. Its totient is φ = 687131706.

The previous prime is 687131689. The next prime is 687131723. The reversal of 687131707 is 707131786.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 687131707 - 2⁷ = 687131579 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 687131707.

It is not a weakly prime, because it can be changed into another prime (687131777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343565853 + 343565854.

It is an arithmetic number, because the mean of its divisors is an integer number (343565854).

Almost surely, 2^687131707 is an apocalyptic number.

687131707 is a deficient number, since it is larger than the sum of its proper divisors (1).

687131707 is an equidigital number, since it uses as much as digits as its factorization.

687131707 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 49392, while the sum is 40.

The square root of 687131707 is about 26213.1971914912. The cubic root of 687131707 is about 882.4294553684.

The spelling of 687131707 in words is "six hundred eighty-seven million, one hundred thirty-one thousand, seven hundred seven".