642103521 has 8 divisors (see below), whose sum is σ = 866453280. Its totient is φ = 422911392.

The previous prime is 642103493. The next prime is 642103531. The reversal of 642103521 is 125301246.

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

It is not a de Polignac number, because 642103521 - 2¹⁵ = 642070753 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 642103491 and 642103500.

It is not an unprimeable number, because it can be changed into a prime (642103531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1289116 + ... + 1289613.

It is an arithmetic number, because the mean of its divisors is an integer number (108306660).

Almost surely, 2^642103521 is an apocalyptic number.

It is an amenable number.

642103521 is a deficient number, since it is larger than the sum of its proper divisors (224349759).

642103521 is a wasteful number, since it uses less digits than its factorization.

642103521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2578815.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 642103521 is about 25339.7616602840. The cubic root of 642103521 is about 862.7169890513.

Adding to 642103521 its reverse (125301246), we get a palindrome (767404767).

The spelling of 642103521 in words is "six hundred forty-two million, one hundred three thousand, five hundred twenty-one".