5681949397 has 4 divisors (see below), whose sum is σ = 5689964140. Its totient is φ = 5673934656.

The previous prime is 5681949353. The next prime is 5681949401. The reversal of 5681949397 is 7939491865.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7939491865 = 5 ⋅1587898373.

It can be written as a sum of positive squares in 2 ways, for example, as 1258901361 + 4423048036 = 35481^2 + 66506^2 .

It is a cyclic number.

It is not a de Polignac number, because 5681949397 - 2⁷ = 5681949269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5681949307) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4006308 + ... + 4007725.

It is an arithmetic number, because the mean of its divisors is an integer number (1422491035).

Almost surely, 2^5681949397 is an apocalyptic number.

It is an amenable number.

5681949397 is a deficient number, since it is larger than the sum of its proper divisors (8014743).

5681949397 is an equidigital number, since it uses as much as digits as its factorization.

5681949397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8014742.

The product of its digits is 14696640, while the sum is 61.

The square root of 5681949397 is about 75378.7065224656. The cubic root of 5681949397 is about 1784.4283750010.

The spelling of 5681949397 in words is "five billion, six hundred eighty-one million, nine hundred forty-nine thousand, three hundred ninety-seven".