6521694421 has 12 divisors (see below), whose sum is σ = 7269448032. Its totient is φ = 5845301000.

The previous prime is 6521694401. The next prime is 6521694449. The reversal of 6521694421 is 1244961256.

It is not a de Polignac number, because 6521694421 - 2⁹ = 6521693909 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6521694401) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 370975 + ... + 388156.

It is an arithmetic number, because the mean of its divisors is an integer number (605787336).

Almost surely, 2^6521694421 is an apocalyptic number.

It is an amenable number.

6521694421 is a deficient number, since it is larger than the sum of its proper divisors (747753611).

6521694421 is a wasteful number, since it uses less digits than its factorization.

6521694421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 759224 (or 759213 counting only the distinct ones).

The product of its digits is 103680, while the sum is 40.

The square root of 6521694421 is about 80757.0084946192. The cubic root of 6521694421 is about 1868.3295463058.

The spelling of 6521694421 in words is "six billion, five hundred twenty-one million, six hundred ninety-four thousand, four hundred twenty-one".