688361409 has 24 divisors (see below), whose sum is σ = 1035029632. Its totient is φ = 457170480.

The previous prime is 688361407. The next prime is 688361419. The reversal of 688361409 is 904163886.

It is not a de Polignac number, because 688361409 - 2¹ = 688361407 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688361407) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 60627 + ... + 71079.

Almost surely, 2^688361409 is an apocalyptic number.

It is an amenable number.

688361409 is a deficient number, since it is larger than the sum of its proper divisors (346668223).

688361409 is a wasteful number, since it uses less digits than its factorization.

688361409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10739 (or 10727 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The square root of 688361409 is about 26236.6424871781. The cubic root of 688361409 is about 882.9555449951.

The spelling of 688361409 in words is "six hundred eighty-eight million, three hundred sixty-one thousand, four hundred nine".