690655679 has 4 divisors (see below), whose sum is σ = 789320784. Its totient is φ = 591990576.

The previous prime is 690655673. The next prime is 690655687. The reversal of 690655679 is 976556096.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 690655679 - 2¹⁶ = 690590143 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 690655679.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (690655673) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49332542 + ... + 49332555.

It is an arithmetic number, because the mean of its divisors is an integer number (197330196).

Almost surely, 2^690655679 is an apocalyptic number.

690655679 is a deficient number, since it is larger than the sum of its proper divisors (98665105).

690655679 is an equidigital number, since it uses as much as digits as its factorization.

690655679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98665104.

The product of its (nonzero) digits is 3061800, while the sum is 53.

The square root of 690655679 is about 26280.3287460412. The cubic root of 690655679 is about 883.9354043113.

The spelling of 690655679 in words is "six hundred ninety million, six hundred fifty-five thousand, six hundred seventy-nine".