6521000642 has 16 divisors (see below), whose sum is σ = 10538522232. Its totient is φ = 3008378880.

The previous prime is 6521000599. The next prime is 6521000693. The reversal of 6521000642 is 2460001256.

It can be written as a sum of positive squares in 4 ways, for example, as 5896550521 + 624450121 = 76789^2 + 24989^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

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, 7298 + ... + 114434.

Almost surely, 2^6521000642 is an apocalyptic number.

6521000642 is a deficient number, since it is larger than the sum of its proper divisors (4017521590).

6521000642 is a wasteful number, since it uses less digits than its factorization.

6521000642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109493.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 6521000642 is about 80752.7129079884. The cubic root of 6521000642 is about 1868.2632928811.

Adding to 6521000642 its reverse (2460001256), we get a palindrome (8981001898).

The spelling of 6521000642 in words is "six billion, five hundred twenty-one million, six hundred forty-two", and thus it is an aban number.