641532421 has 4 divisors (see below), whose sum is σ = 644409472. Its totient is φ = 638655372.

The previous prime is 641532413. The next prime is 641532433. The reversal of 641532421 is 124235146.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 641532421 - 2³ = 641532413 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 641532421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641532821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1438191 + ... + 1438636.

It is an arithmetic number, because the mean of its divisors is an integer number (161102368).

Almost surely, 2^641532421 is an apocalyptic number.

It is an amenable number.

641532421 is a deficient number, since it is larger than the sum of its proper divisors (2877051).

641532421 is a wasteful number, since it uses less digits than its factorization.

641532421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2877050.

The product of its digits is 5760, while the sum is 28.

The square root of 641532421 is about 25328.4903024243. The cubic root of 641532421 is about 862.4611404743.

Adding to 641532421 its reverse (124235146), we get a palindrome (765767567).

The spelling of 641532421 in words is "six hundred forty-one million, five hundred thirty-two thousand, four hundred twenty-one".