427989415681 has 3 divisors (see below), whose sum is σ = 427990069891. Its totient is φ = 427988761472.

The previous prime is 427989415639. The next prime is 427989415723. The reversal of 427989415681 is 186514989724.

The square root of 427989415681 is 654209.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (427989415639) and next prime (427989415723).

It can be written as a sum of positive squares in only one way, i.e., 111695655681 + 316293760000 = 334209^2 + 562400^2 .

It is not a de Polignac number, because 427989415681 - 2⁹ = 427989415169 is a prime.

It is a super-2 number, since 2×427989415681² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (427989416681) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 327105 + ... + 981313.

Almost surely, 2^427989415681 is an apocalyptic number.

427989415681 is the 654209-th square number.

427989415681 is the 327105-th centered octagonal number.

It is an amenable number.

427989415681 is a deficient number, since it is larger than the sum of its proper divisors (654210).

427989415681 is an frugal number, since it uses more digits than its factorization.

427989415681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1308418 (or 654209 counting only the distinct ones).

The product of its digits is 34836480, while the sum is 64.

Multiplying 427989415681 by its sum of digits (64), we get a square (27391322603584 = 5233672²).

The spelling of 427989415681 in words is "four hundred twenty-seven billion, nine hundred eighty-nine million, four hundred fifteen thousand, six hundred eighty-one".