1697399978 has 8 divisors (see below), whose sum is σ = 2628232320. Its totient is φ = 821322540.

The previous prime is 1697399929. The next prime is 1697399981. The reversal of 1697399978 is 8799937961.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13688648 + ... + 13688771.

It is an arithmetic number, because the mean of its divisors is an integer number (328529040).

Almost surely, 2^1697399978 is an apocalyptic number.

1697399978 is a deficient number, since it is larger than the sum of its proper divisors (930832342).

1697399978 is a wasteful number, since it uses less digits than its factorization.

1697399978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27377452.

The product of its digits is 46294416, while the sum is 68.

The square root of 1697399978 is about 41199.5142932535. The cubic root of 1697399978 is about 1192.8744339120.

The spelling of 1697399978 in words is "one billion, six hundred ninety-seven million, three hundred ninety-nine thousand, nine hundred seventy-eight".