641812511 has 4 divisors (see below), whose sum is σ = 649936800. Its totient is φ = 633688224.

The previous prime is 641812487. The next prime is 641812517. The reversal of 641812511 is 115218146.

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 641812511 - 2¹⁰ = 641811487 is a prime.

It is a super-2 number, since 2×641812511² = 823846598552250242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641812517) 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, 4062026 + ... + 4062183.

It is an arithmetic number, because the mean of its divisors is an integer number (162484200).

Almost surely, 2^641812511 is an apocalyptic number.

641812511 is a deficient number, since it is larger than the sum of its proper divisors (8124289).

641812511 is an equidigital number, since it uses as much as digits as its factorization.

641812511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8124288.

The product of its digits is 1920, while the sum is 29.

The square root of 641812511 is about 25334.0188481812. The cubic root of 641812511 is about 862.5866376878.

The spelling of 641812511 in words is "six hundred forty-one million, eight hundred twelve thousand, five hundred eleven".