684978136 has 8 divisors (see below), whose sum is σ = 1284334020. Its totient is φ = 342489064.

The previous prime is 684978131. The next prime is 684978137. The reversal of 684978136 is 631879486.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684978131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42811126 + ... + 42811141.

Almost surely, 2^684978136 is an apocalyptic number.

It is an amenable number.

684978136 is a deficient number, since it is larger than the sum of its proper divisors (599355884).

684978136 is a wasteful number, since it uses less digits than its factorization.

684978136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85622273 (or 85622269 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 52.

The square root of 684978136 is about 26172.0869630223. The cubic root of 684978136 is about 881.5066030342.

The spelling of 684978136 in words is "six hundred eighty-four million, nine hundred seventy-eight thousand, one hundred thirty-six".