688943540 has 24 divisors (see below), whose sum is σ = 1456369152. Its totient is φ = 273751200.

The previous prime is 688943533. The next prime is 688943543. The reversal of 688943540 is 45349886.

688943540 = T₉₅ + T₉₆ + ... + T₁₆₀₄.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688943543) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 111044 + ... + 117083.

It is an arithmetic number, because the mean of its divisors is an integer number (60682048).

Almost surely, 2^688943540 is an apocalyptic number.

It is an amenable number.

688943540 is an abundant number, since it is smaller than the sum of its proper divisors (767425612).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

688943540 is a wasteful number, since it uses less digits than its factorization.

688943540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228287 (or 228285 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 47.

The square root of 688943540 is about 26247.7339974330. The cubic root of 688943540 is about 883.2043730885.

The spelling of 688943540 in words is "six hundred eighty-eight million, nine hundred forty-three thousand, five hundred forty".