6821463781 has 16 divisors (see below), whose sum is σ = 7753636800. Its totient is φ = 5944377600.

The previous prime is 6821463749. The next prime is 6821463787. The reversal of 6821463781 is 1873641286.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 6821463781 - 2⁵ = 6821463749 is a prime.

It is a super-2 number, since 2×6821463781² = 93064736230989631922, 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 (6821463787) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32580 + ... + 121261.

It is an arithmetic number, because the mean of its divisors is an integer number (484602300).

Almost surely, 2^6821463781 is an apocalyptic number.

It is an amenable number.

6821463781 is a deficient number, since it is larger than the sum of its proper divisors (932173019).

6821463781 is a wasteful number, since it uses less digits than its factorization.

6821463781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154020.

The product of its digits is 387072, while the sum is 46.

The square root of 6821463781 is about 82592.1532653072. The cubic root of 6821463781 is about 1896.5277099830.

The spelling of 6821463781 in words is "six billion, eight hundred twenty-one million, four hundred sixty-three thousand, seven hundred eighty-one".