6401928521 has 2 divisors, whose sum is σ = 6401928522. Its totient is φ = 6401928520.

The previous prime is 6401928461. The next prime is 6401928613. The reversal of 6401928521 is 1258291046.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3699072400 + 2702856121 = 60820^2 + 51989^2 .

It is a cyclic number.

It is not a de Polignac number, because 6401928521 - 2³⁰ = 5328186697 is a prime.

It is not a weakly prime, because it can be changed into another prime (6401928821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3200964260 + 3200964261.

It is an arithmetic number, because the mean of its divisors is an integer number (3200964261).

Almost surely, 2^6401928521 is an apocalyptic number.

It is an amenable number.

6401928521 is a deficient number, since it is larger than the sum of its proper divisors (1).

6401928521 is an equidigital number, since it uses as much as digits as its factorization.

6401928521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34560, while the sum is 38.

The square root of 6401928521 is about 80012.0523483806. The cubic root of 6401928521 is about 1856.8220022488.

The spelling of 6401928521 in words is "six billion, four hundred one million, nine hundred twenty-eight thousand, five hundred twenty-one".