6821400679 has 4 divisors (see below), whose sum is σ = 6821587584. Its totient is φ = 6821213776.

The previous prime is 6821400661. The next prime is 6821400709. The reversal of 6821400679 is 9760041286.

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

It is a cyclic number.

It is not a de Polignac number, because 6821400679 - 2¹⁷ = 6821269607 is a prime.

It is a super-2 number, since 2×6821400679² = 93063014446923322082, 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 (6821400629) 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, 18862 + ... + 118315.

It is an arithmetic number, because the mean of its divisors is an integer number (1705396896).

Almost surely, 2^6821400679 is an apocalyptic number.

6821400679 is a deficient number, since it is larger than the sum of its proper divisors (186905).

6821400679 is a wasteful number, since it uses less digits than its factorization.

6821400679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186904.

The product of its (nonzero) digits is 145152, while the sum is 43.

The square root of 6821400679 is about 82591.7712547685. The cubic root of 6821400679 is about 1896.5218620172.

The spelling of 6821400679 in words is "six billion, eight hundred twenty-one million, four hundred thousand, six hundred seventy-nine".