65689640 has 32 divisors (see below), whose sum is σ = 152901000. Its totient is φ = 25369344.

The previous prime is 65689639. The next prime is 65689699. The reversal of 65689640 is 4698656.

It can be written as a sum of positive squares in 4 ways, for example, as 50495236 + 15194404 = 7106^2 + 3898^2 .

It is a junction number, because it is equal to n+sod(n) for n = 65689591 and 65689600.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27155 + ... + 29474.

Almost surely, 2^65689640 is an apocalyptic number.

It is an amenable number.

65689640 is an abundant number, since it is smaller than the sum of its proper divisors (87211360).

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

65689640 is a wasteful number, since it uses less digits than its factorization.

65689640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56669 (or 56665 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 44.

The square root of 65689640 is about 8104.9145584639. The cubic root of 65689640 is about 403.4895523686.

The spelling of 65689640 in words is "sixty-five million, six hundred eighty-nine thousand, six hundred forty".