6640725426 has 16 divisors (see below), whose sum is σ = 13329401664. Its totient is φ = 2205583344.

The previous prime is 6640725391. The next prime is 6640725431. The reversal of 6640725426 is 6245270466.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1996150 + ... + 1999473.

It is an arithmetic number, because the mean of its divisors is an integer number (833087604).

Almost surely, 2^6640725426 is an apocalyptic number.

6640725426 is an abundant number, since it is smaller than the sum of its proper divisors (6688676238).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6640725426 is a wasteful number, since it uses less digits than its factorization.

6640725426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3995905.

The product of its (nonzero) digits is 483840, while the sum is 42.

The square root of 6640725426 is about 81490.6462485112. The cubic root of 6640725426 is about 1879.6277203478.

The spelling of 6640725426 in words is "six billion, six hundred forty million, seven hundred twenty-five thousand, four hundred twenty-six".