20509448402 has 4 divisors (see below), whose sum is σ = 30764172606. Its totient is φ = 10254724200.

The previous prime is 20509448389. The next prime is 20509448417. The reversal of 20509448402 is 20484490502.

It is a happy number.

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., 16009587841 + 4499860561 = 126529^2 + 67081^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5127362099 + ... + 5127362102.

Almost surely, 2^20509448402 is an apocalyptic number.

20509448402 is a deficient number, since it is larger than the sum of its proper divisors (10254724204).

20509448402 is a wasteful number, since it uses less digits than its factorization.

20509448402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10254724203.

The product of its (nonzero) digits is 92160, while the sum is 38.

The spelling of 20509448402 in words is "twenty billion, five hundred nine million, four hundred forty-eight thousand, four hundred two".