697778 has 4 divisors (see below), whose sum is σ = 1046670. Its totient is φ = 348888.

The previous prime is 697759. The next prime is 697787. The reversal of 697778 is 877796.

697778 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in only one way, i.e., 677329 + 20449 = 823^2 + 143^2 .

It is a Curzon number.

It is an unprimeable number.

697778 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 174443 + ... + 174446.

2⁶⁹⁷⁷⁷⁸ is an apocalyptic number.

697778 is a deficient number, since it is larger than the sum of its proper divisors (348892).

697778 is a wasteful number, since it uses less digits than its factorization.

697778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348891.

The product of its digits is 148176, while the sum is 44.

The square root of 697778 is about 835.3310720906. The cubic root of 697778 is about 88.6963518923.

The spelling of 697778 in words is "six hundred ninety-seven thousand, seven hundred seventy-eight".