690640605 has 24 divisors (see below), whose sum is σ = 1206546432. Its totient is φ = 365438304.

The previous prime is 690640591. The next prime is 690640649. The reversal of 690640605 is 506046096.

It is a happy number.

690640605 is a `hidden beast` number, since 6 + 9 + 0 + 6 + 40 + 605 = 666.

It is not a de Polignac number, because 690640605 - 2¹⁸ = 690378461 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 690640605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 54709 + ... + 66138.

It is an arithmetic number, because the mean of its divisors is an integer number (50272768).

Almost surely, 2^690640605 is an apocalyptic number.

It is an amenable number.

690640605 is a deficient number, since it is larger than the sum of its proper divisors (515905827).

690640605 is a wasteful number, since it uses less digits than its factorization.

690640605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120985 (or 120982 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 690640605 is about 26280.0419520213. The cubic root of 690640605 is about 883.9289734468.

The spelling of 690640605 in words is "six hundred ninety million, six hundred forty thousand, six hundred five".