643261036402 has 32 divisors (see below), whose sum is σ = 971421517440. Its totient is φ = 319462846080.

The previous prime is 643261036357. The next prime is 643261036417. The reversal of 643261036402 is 204630162346.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 468506988 + ... + 468508360.

It is an arithmetic number, because the mean of its divisors is an integer number (30356922420).

Almost surely, 2^643261036402 is an apocalyptic number.

643261036402 is a deficient number, since it is larger than the sum of its proper divisors (328160481038).

643261036402 is a wasteful number, since it uses less digits than its factorization.

643261036402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3618.

The product of its (nonzero) digits is 124416, while the sum is 37.

Adding to 643261036402 its reverse (204630162346), we get a palindrome (847891198748).

The spelling of 643261036402 in words is "six hundred forty-three billion, two hundred sixty-one million, thirty-six thousand, four hundred two".