643658477 has 8 divisors (see below), whose sum is σ = 802483392. Its totient is φ = 501552000.

The previous prime is 643658453. The next prime is 643658501. The reversal of 643658477 is 774856346.

It is an interprime number because it is at equal distance from previous prime (643658453) and next prime (643658501).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 643658477 - 2²⁰ = 642609901 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643658077) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4179524 + ... + 4179677.

It is an arithmetic number, because the mean of its divisors is an integer number (100310424).

Almost surely, 2^643658477 is an apocalyptic number.

It is an amenable number.

643658477 is a deficient number, since it is larger than the sum of its proper divisors (158824915).

643658477 is a wasteful number, since it uses less digits than its factorization.

643658477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8359219.

The product of its digits is 3386880, while the sum is 50.

The square root of 643658477 is about 25370.4252427901. The cubic root of 643658477 is about 863.4128298798.

The spelling of 643658477 in words is "six hundred forty-three million, six hundred fifty-eight thousand, four hundred seventy-seven".