6405749842 has 4 divisors (see below), whose sum is σ = 9608624766. Its totient is φ = 3202874920.

The previous prime is 6405749827. The next prime is 6405749843. The reversal of 6405749842 is 2489475046.

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

It can be written as a sum of positive squares in only one way, i.e., 3893635201 + 2512114641 = 62399^2 + 50121^2 .

It is not an unprimeable number, because it can be changed into a prime (6405749843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1601437459 + ... + 1601437462.

Almost surely, 2^6405749842 is an apocalyptic number.

6405749842 is a deficient number, since it is larger than the sum of its proper divisors (3202874924).

6405749842 is a wasteful number, since it uses less digits than its factorization.

6405749842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3202874923.

The product of its (nonzero) digits is 1935360, while the sum is 49.

The square root of 6405749842 is about 80035.9284446679. The cubic root of 6405749842 is about 1857.1913754036.

The spelling of 6405749842 in words is "six billion, four hundred five million, seven hundred forty-nine thousand, eight hundred forty-two".