689405945 has 8 divisors (see below), whose sum is σ = 833239680. Its totient is φ = 547556400.

The previous prime is 689405929. The next prime is 689405963. The reversal of 689405945 is 549504986.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 689405945 - 2⁴ = 689405929 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 689405893 and 689405902.

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, 495281 + ... + 496670.

It is an arithmetic number, because the mean of its divisors is an integer number (104154960).

Almost surely, 2^689405945 is an apocalyptic number.

It is an amenable number.

689405945 is a deficient number, since it is larger than the sum of its proper divisors (143833735).

689405945 is a wasteful number, since it uses less digits than its factorization.

689405945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 992095.

The product of its (nonzero) digits is 1555200, while the sum is 50.

The square root of 689405945 is about 26256.5409945789. The cubic root of 689405945 is about 883.4019252143.

The spelling of 689405945 in words is "six hundred eighty-nine million, four hundred five thousand, nine hundred forty-five".