697971689809 has 9 divisors (see below), whose sum is σ = 714617856603. Its totient is φ = 681704701272.

The previous prime is 697971689801. The next prime is 697971689827. The reversal of 697971689809 is 908986179796.

It is a happy number.

The square root of 697971689809 is 835447.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 3516134209 + 694455555600 = 59297^2 + 833340^2 .

It is not a de Polignac number, because 697971689809 - 2³ = 697971689801 is a prime.

It is not an unprimeable number, because it can be changed into a prime (697971689801) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 35914507 + ... + 35933935.

It is an arithmetic number, because the mean of its divisors is an integer number (79401984067).

Almost surely, 2^697971689809 is an apocalyptic number.

697971689809 is the 835447-th square number.

697971689809 is the 417724-th centered octagonal number.

It is an amenable number.

697971689809 is a deficient number, since it is larger than the sum of its proper divisors (16646166794).

697971689809 is an frugal number, since it uses more digits than its factorization.

697971689809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38944 (or 19472 counting only the distinct ones).

The product of its (nonzero) digits is 740710656, while the sum is 79.

The spelling of 697971689809 in words is "six hundred ninety-seven billion, nine hundred seventy-one million, six hundred eighty-nine thousand, eight hundred nine".