688920887 has 2 divisors, whose sum is σ = 688920888. Its totient is φ = 688920886.

The previous prime is 688920853. The next prime is 688920901. The reversal of 688920887 is 788029886.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 688920887 - 2¹² = 688916791 is a prime.

It is a super-2 number, since 2×688920887² = 949223977089733538, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688920847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344460443 + 344460444.

It is an arithmetic number, because the mean of its divisors is an integer number (344460444).

Almost surely, 2^688920887 is an apocalyptic number.

688920887 is a deficient number, since it is larger than the sum of its proper divisors (1).

688920887 is an equidigital number, since it uses as much as digits as its factorization.

688920887 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3096576, while the sum is 56.

The square root of 688920887 is about 26247.3024709207. The cubic root of 688920887 is about 883.1946928333.

The spelling of 688920887 in words is "six hundred eighty-eight million, nine hundred twenty thousand, eight hundred eighty-seven".