6381729261 has 10 divisors (see below), whose sum is σ = 9533200622. Its totient is φ = 4254486120.

The previous prime is 6381729227. The next prime is 6381729307. The reversal of 6381729261 is 1629271836.

6381729261 is a `hidden beast` number, since 6 + 381 + 7 + 2 + 9 + 261 = 666.

It can be written as a sum of positive squares in only one way, i.e., 5302606761 + 1079122500 = 72819^2 + 32850^2 .

It is not a de Polignac number, because 6381729261 - 2¹⁰ = 6381728237 is a prime.

It is a super-2 number, since 2×6381729261² = 81452936721407212242, 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 (6381729061) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 39393310 + ... + 39393471.

Almost surely, 2^6381729261 is an apocalyptic number.

It is an amenable number.

6381729261 is a deficient number, since it is larger than the sum of its proper divisors (3151471361).

6381729261 is an equidigital number, since it uses as much as digits as its factorization.

6381729261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78786793 (or 78786784 counting only the distinct ones).

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

The square root of 6381729261 is about 79885.7262657103. The cubic root of 6381729261 is about 1854.8670732966.

The spelling of 6381729261 in words is "six billion, three hundred eighty-one million, seven hundred twenty-nine thousand, two hundred sixty-one".