641530819 has 4 divisors (see below), whose sum is σ = 679267944. Its totient is φ = 603793696.

The previous prime is 641530817. The next prime is 641530823. The reversal of 641530819 is 918035146.

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

It is a cyclic number.

It is not a de Polignac number, because 641530819 - 2¹ = 641530817 is a prime.

It is a super-2 number, since 2×641530819² = 823123583453621522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641530817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18868537 + ... + 18868570.

It is an arithmetic number, because the mean of its divisors is an integer number (169816986).

Almost surely, 2^641530819 is an apocalyptic number.

641530819 is a deficient number, since it is larger than the sum of its proper divisors (37737125).

641530819 is a wasteful number, since it uses less digits than its factorization.

641530819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37737124.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 641530819 is about 25328.4586779377. The cubic root of 641530819 is about 862.4604225766.

The spelling of 641530819 in words is "six hundred forty-one million, five hundred thirty thousand, eight hundred nineteen".