6561500402 has 4 divisors (see below), whose sum is σ = 9842250606. Its totient is φ = 3280750200.

The previous prime is 6561500401. The next prime is 6561500411. The reversal of 6561500402 is 2040051656.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 5979774241 + 581726161 = 77329^2 + 24119^2 .

It is not an unprimeable number, because it can be changed into a prime (6561500401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1640375099 + ... + 1640375102.

Almost surely, 2^6561500402 is an apocalyptic number.

6561500402 is a deficient number, since it is larger than the sum of its proper divisors (3280750204).

6561500402 is a wasteful number, since it uses less digits than its factorization.

6561500402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3280750203.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 6561500402 is about 81003.0888423398. The cubic root of 6561500402 is about 1872.1230334145.

The spelling of 6561500402 in words is "six billion, five hundred sixty-one million, five hundred thousand, four hundred two".