6541963381 has 4 divisors (see below), whose sum is σ = 6542131500. Its totient is φ = 6541795264.

The previous prime is 6541963367. The next prime is 6541963399. The reversal of 6541963381 is 1833691456.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2890782756 + 3651180625 = 53766^2 + 60425^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6541963381 is a prime.

It is a super-2 number, since 2×6541963381² = 85594569756689902322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6541963481) 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, 7695 + ... + 114643.

It is an arithmetic number, because the mean of its divisors is an integer number (1635532875).

Almost surely, 2^6541963381 is an apocalyptic number.

It is an amenable number.

6541963381 is a deficient number, since it is larger than the sum of its proper divisors (168119).

6541963381 is a wasteful number, since it uses less digits than its factorization.

6541963381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168118.

The product of its digits is 466560, while the sum is 46.

The square root of 6541963381 is about 80882.4046440263. The cubic root of 6541963381 is about 1870.2630894678.

The spelling of 6541963381 in words is "six billion, five hundred forty-one million, nine hundred sixty-three thousand, three hundred eighty-one".