6421559377 has 4 divisors (see below), whose sum is σ = 6424883380. Its totient is φ = 6418235376.

The previous prime is 6421559357. The next prime is 6421559393. The reversal of 6421559377 is 7739551246.

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 3829629456 + 2591929921 = 61884^2 + 50911^2 .

It is a cyclic number.

It is not a de Polignac number, because 6421559377 - 2²³ = 6413170769 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6421559377.

It is not an unprimeable number, because it can be changed into a prime (6421559357) 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, 1659102 + ... + 1662967.

It is an arithmetic number, because the mean of its divisors is an integer number (1606220845).

Almost surely, 2^6421559377 is an apocalyptic number.

It is an amenable number.

6421559377 is a deficient number, since it is larger than the sum of its proper divisors (3324003).

6421559377 is a wasteful number, since it uses less digits than its factorization.

6421559377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3324002.

The product of its digits is 1587600, while the sum is 49.

The square root of 6421559377 is about 80134.6328187757. The cubic root of 6421559377 is about 1858.7179835827.

The spelling of 6421559377 in words is "six billion, four hundred twenty-one million, five hundred fifty-nine thousand, three hundred seventy-seven".