688961851 has 2 divisors, whose sum is σ = 688961852. Its totient is φ = 688961850.

The previous prime is 688961813. The next prime is 688961857. The reversal of 688961851 is 158169886.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 688961851 - 2¹³ = 688953659 is a prime.

It is not a weakly prime, because it can be changed into another prime (688961857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344480925 + 344480926.

It is an arithmetic number, because the mean of its divisors is an integer number (344480926).

Almost surely, 2^688961851 is an apocalyptic number.

688961851 is a deficient number, since it is larger than the sum of its proper divisors (1).

688961851 is an equidigital number, since it uses as much as digits as its factorization.

688961851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 829440, while the sum is 52.

The square root of 688961851 is about 26248.0828061784. The cubic root of 688961851 is about 883.2121977317.

The spelling of 688961851 in words is "six hundred eighty-eight million, nine hundred sixty-one thousand, eight hundred fifty-one".