1739640681 has 9 divisors (see below), whose sum is σ = 2512995069. Its totient is φ = 1159677036.

The previous prime is 1739640631. The next prime is 1739640691. The reversal of 1739640681 is 1860469371.

It is a happy number.

The square root of 1739640681 is 41709.

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

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 1739640681 - 2¹⁵ = 1739607913 is a prime.

It is a super-2 number, since 2×1739640681² = 6052699397980287522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1739640631) 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, 118176 + ... + 132078.

Almost surely, 2^1739640681 is an apocalyptic number.

1739640681 is the 41709-th square number.

1739640681 is the 20855-th centered octagonal number.

It is an amenable number.

1739640681 is a deficient number, since it is larger than the sum of its proper divisors (773354388).

1739640681 is an frugal number, since it uses more digits than its factorization.

1739640681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27812 (or 13906 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The cubic root of 1739640681 is about 1202.6885738934.

The spelling of 1739640681 in words is "one billion, seven hundred thirty-nine million, six hundred forty thousand, six hundred eighty-one".