643245704676 has 135 divisors (see below), whose sum is σ = 1786987675627. Its totient is φ = 201725579520.

The previous prime is 643245704657. The next prime is 643245704683. The reversal of 643245704676 is 676407542346.

The square root of 643245704676 is 802026.

It is a perfect power (a square), and thus also a powerful number.

643245704676 is a `hidden beast` number, since 6 + 4 + 3 + 2 + 4 + 570 + 4 + 67 + 6 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 234188244900 + 409057459776 = 483930^2 + 639576^2 .

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 245418646 + ... + 245421266.

Almost surely, 2^643245704676 is an apocalyptic number.

643245704676 is the 802026-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643245704676

643245704676 is an abundant number, since it is smaller than the sum of its proper divisors (1143741970951).

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

643245704676 is an equidigital number, since it uses as much as digits as its factorization.

643245704676 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5292 (or 2643 counting only the distinct ones).

The product of its (nonzero) digits is 20321280, while the sum is 54.

It can be divided in two parts, 643245 and 704676, that added together give a square (1347921 = 1161²).

The spelling of 643245704676 in words is "six hundred forty-three billion, two hundred forty-five million, seven hundred four thousand, six hundred seventy-six".