21336959649 has 16 divisors (see below), whose sum is σ = 28798463232. Its totient is φ = 14050124688.

The previous prime is 21336959639. The next prime is 21336959653. The reversal of 21336959649 is 94695963312.

It is a happy number.

It is not a de Polignac number, because 21336959649 - 2⁸ = 21336959393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21336959629) by changing a digit.

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 in 15 ways as a sum of consecutive naturals, for example, 1783602 + ... + 1795524.

It is an arithmetic number, because the mean of its divisors is an integer number (1799903952).

Almost surely, 2^21336959649 is an apocalyptic number.

It is an amenable number.

21336959649 is a deficient number, since it is larger than the sum of its proper divisors (7461503583).

21336959649 is a wasteful number, since it uses less digits than its factorization.

21336959649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19196.

The product of its digits is 9447840, while the sum is 57.

The spelling of 21336959649 in words is "twenty-one billion, three hundred thirty-six million, nine hundred fifty-nine thousand, six hundred forty-nine".