641781429 has 4 divisors (see below), whose sum is σ = 855708576. Its totient is φ = 427854284.

The previous prime is 641781401. The next prime is 641781473. The reversal of 641781429 is 924187146.

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 641781429 - 2¹¹ = 641779381 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641581429) 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, 106963569 + ... + 106963574.

It is an arithmetic number, because the mean of its divisors is an integer number (213927144).

Almost surely, 2^641781429 is an apocalyptic number.

It is an amenable number.

641781429 is a deficient number, since it is larger than the sum of its proper divisors (213927147).

641781429 is a wasteful number, since it uses less digits than its factorization.

641781429 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213927146.

The product of its digits is 96768, while the sum is 42.

The square root of 641781429 is about 25333.4053968273. The cubic root of 641781429 is about 862.5727128784.

The spelling of 641781429 in words is "six hundred forty-one million, seven hundred eighty-one thousand, four hundred twenty-nine".