6421593994 has 8 divisors (see below), whose sum is σ = 9633022308. Its totient is φ = 3210586560.

The previous prime is 6421593947. The next prime is 6421594009. The reversal of 6421593994 is 4993951246.

It can be written as a sum of positive squares in 2 ways, for example, as 6416811025 + 4782969 = 80105^2 + 2187^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63817 + ... + 130060.

Almost surely, 2^6421593994 is an apocalyptic number.

6421593994 is a deficient number, since it is larger than the sum of its proper divisors (3211428314).

6421593994 is a wasteful number, since it uses less digits than its factorization.

6421593994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210440.

The product of its digits is 2099520, while the sum is 52.

The square root of 6421593994 is about 80134.8488112382. The cubic root of 6421593994 is about 1858.7213235360.

The spelling of 6421593994 in words is "six billion, four hundred twenty-one million, five hundred ninety-three thousand, nine hundred ninety-four".