643674465 has 32 divisors (see below), whose sum is σ = 1307784960. Its totient is φ = 294250752.

The previous prime is 643674463. The next prime is 643674467. The reversal of 643674465 is 564476346.

It is a happy number.

643674465 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (643674463) and next prime (643674467).

It is not a de Polignac number, because 643674465 - 2¹ = 643674463 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 643674465.

It is not an unprimeable number, because it can be changed into a prime (643674461) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 339624 + ... + 341513.

It is an arithmetic number, because the mean of its divisors is an integer number (40868280).

Almost surely, 2^643674465 is an apocalyptic number.

It is an amenable number.

643674465 is an abundant number, since it is smaller than the sum of its proper divisors (664110495).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643674465 is a wasteful number, since it uses less digits than its factorization.

643674465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 681158 (or 681152 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 45.

The square root of 643674465 is about 25370.7403321228. The cubic root of 643674465 is about 863.4199786657.

The spelling of 643674465 in words is "six hundred forty-three million, six hundred seventy-four thousand, four hundred sixty-five".