6414640021 has 4 divisors (see below), whose sum is σ = 6415376044. Its totient is φ = 6413904000.

The previous prime is 6414639983. The next prime is 6414640031. The reversal of 6414640021 is 1200464146.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5352531921 + 1062108100 = 73161^2 + 32590^2 .

It is a cyclic number.

It is not a de Polignac number, because 6414640021 - 2¹⁵ = 6414607253 is a prime.

It is a super-2 number, since 2×6414640021² = 82295213198029760882, 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 (6414640031) 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, 354780 + ... + 372421.

It is an arithmetic number, because the mean of its divisors is an integer number (1603844011).

Almost surely, 2^6414640021 is an apocalyptic number.

It is an amenable number.

6414640021 is a deficient number, since it is larger than the sum of its proper divisors (736023).

6414640021 is an equidigital number, since it uses as much as digits as its factorization.

6414640021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 736022.

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 6414640021 is about 80091.4478643007. The cubic root of 6414640021 is about 1858.0501419772.

The spelling of 6414640021 in words is "six billion, four hundred fourteen million, six hundred forty thousand, twenty-one".