688552261 has 4 divisors (see below), whose sum is σ = 692776672. Its totient is φ = 684327852.

The previous prime is 688552259. The next prime is 688552331. The reversal of 688552261 is 162255886.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 688552261 - 2¹ = 688552259 is a prime.

It is a super-2 number, since 2×688552261² = 948208432256424242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688552661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2111961 + ... + 2112286.

It is an arithmetic number, because the mean of its divisors is an integer number (173194168).

Almost surely, 2^688552261 is an apocalyptic number.

It is an amenable number.

688552261 is a deficient number, since it is larger than the sum of its proper divisors (4224411).

688552261 is a wasteful number, since it uses less digits than its factorization.

688552261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4224410.

The product of its digits is 230400, while the sum is 43.

The square root of 688552261 is about 26240.2793620800. The cubic root of 688552261 is about 883.0371388875.

The spelling of 688552261 in words is "six hundred eighty-eight million, five hundred fifty-two thousand, two hundred sixty-one".