641877497 has 4 divisors (see below), whose sum is σ = 643782516. Its totient is φ = 639972480.

The previous prime is 641877493. The next prime is 641877521. The reversal of 641877497 is 794778146.

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

It can be written as a sum of positive squares in 2 ways, for example, as 202094656 + 439782841 = 14216^2 + 20971^2 .

It is a cyclic number.

It is not a de Polignac number, because 641877497 - 2² = 641877493 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641877493) 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, 952004 + ... + 952677.

It is an arithmetic number, because the mean of its divisors is an integer number (160945629).

Almost surely, 2^641877497 is an apocalyptic number.

It is an amenable number.

641877497 is a deficient number, since it is larger than the sum of its proper divisors (1905019).

641877497 is a wasteful number, since it uses less digits than its factorization.

641877497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1905018.

The product of its digits is 2370816, while the sum is 53.

The square root of 641877497 is about 25335.3013994308. The cubic root of 641877497 is about 862.6157501168.

The spelling of 641877497 in words is "six hundred forty-one million, eight hundred seventy-seven thousand, four hundred ninety-seven".