397928717786 has 4 divisors (see below), whose sum is σ = 596893076682. Its totient is φ = 198964358892.

The previous prime is 397928717773. The next prime is 397928717819. The reversal of 397928717786 is 687717829793.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 687717829793 = 443 ⋅1552410451.

It can be written as a sum of positive squares in only one way, i.e., 208237981561 + 189690736225 = 456331^2 + 435535^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99482179445 + ... + 99482179448.

Almost surely, 2^397928717786 is an apocalyptic number.

397928717786 is a deficient number, since it is larger than the sum of its proper divisors (198964358896).

397928717786 is a wasteful number, since it uses less digits than its factorization.

397928717786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198964358895.

The product of its digits is 448084224, while the sum is 74.

It can be divided in two parts, 39792 and 8717786, that added together give a palindrome (8757578).

The spelling of 397928717786 in words is "three hundred ninety-seven billion, nine hundred twenty-eight million, seven hundred seventeen thousand, seven hundred eighty-six".