643040402 has 16 divisors (see below), whose sum is σ = 1022831712. Its totient is φ = 302153280.

The previous prime is 643040383. The next prime is 643040423. The reversal of 643040402 is 204040346.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9377 + ... + 37067.

It is an arithmetic number, because the mean of its divisors is an integer number (63926982).

Almost surely, 2^643040402 is an apocalyptic number.

643040402 is a deficient number, since it is larger than the sum of its proper divisors (379791310).

643040402 is a wasteful number, since it uses less digits than its factorization.

643040402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28393.

The product of its (nonzero) digits is 2304, while the sum is 23.

The square root of 643040402 is about 25358.2413033712. The cubic root of 643040402 is about 863.1363764451.

Adding to 643040402 its reverse (204040346), we get a palindrome (847080748).

The spelling of 643040402 in words is "six hundred forty-three million, forty thousand, four hundred two".