21139887682 has 4 divisors (see below), whose sum is σ = 31709831526. Its totient is φ = 10569943840.

The previous prime is 21139887641. The next prime is 21139887689. The reversal of 21139887682 is 28678893112.

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., 15425888401 + 5713999281 = 124201^2 + 75591^2 .

It is not an unprimeable number, because it can be changed into a prime (21139887689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5284971919 + ... + 5284971922.

Almost surely, 2^21139887682 is an apocalyptic number.

21139887682 is a deficient number, since it is larger than the sum of its proper divisors (10569943844).

21139887682 is a wasteful number, since it uses less digits than its factorization.

21139887682 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10569943843.

The product of its digits is 2322432, while the sum is 55.

The spelling of 21139887682 in words is "twenty-one billion, one hundred thirty-nine million, eight hundred eighty-seven thousand, six hundred eighty-two".