6499051621 has 4 divisors (see below), whose sum is σ = 6546490092. Its totient is φ = 6451613152.

The previous prime is 6499051609. The next prime is 6499051633. The reversal of 6499051621 is 1261509946.

6499051621 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is an interprime number because it is at equal distance from previous prime (6499051609) and next prime (6499051633).

It can be written as a sum of positive squares in 2 ways, for example, as 3734920996 + 2764130625 = 61114^2 + 52575^2 .

It is a cyclic number.

It is not a de Polignac number, because 6499051621 - 2⁵ = 6499051589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6499051651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23719030 + ... + 23719303.

It is an arithmetic number, because the mean of its divisors is an integer number (1636622523).

Almost surely, 2^6499051621 is an apocalyptic number.

It is an amenable number.

6499051621 is a deficient number, since it is larger than the sum of its proper divisors (47438471).

6499051621 is a wasteful number, since it uses less digits than its factorization.

6499051621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47438470.

The product of its (nonzero) digits is 116640, while the sum is 43.

The square root of 6499051621 is about 80616.6956715543. The cubic root of 6499051621 is about 1866.1648089888.

It can be divided in two parts, 64990 and 51621, that added together give a palindrome (116611).

The spelling of 6499051621 in words is "six billion, four hundred ninety-nine million, fifty-one thousand, six hundred twenty-one".