21073919649 has 8 divisors (see below), whose sum is σ = 28112969472. Its totient is φ = 14042074800.

The previous prime is 21073919641. The next prime is 21073919677. The reversal of 21073919649 is 94691937012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21073919649 - 2³ = 21073919641 is a prime.

It is a super-2 number, since 2×21073919649² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21073919641) 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 7 ways as a sum of consecutive naturals, for example, 1794414 + ... + 1806119.

It is an arithmetic number, because the mean of its divisors is an integer number (3514121184).

Almost surely, 2^21073919649 is an apocalyptic number.

It is an amenable number.

21073919649 is a deficient number, since it is larger than the sum of its proper divisors (7039049823).

21073919649 is a wasteful number, since it uses less digits than its factorization.

21073919649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3602487.

The product of its (nonzero) digits is 734832, while the sum is 51.

The spelling of 21073919649 in words is "twenty-one billion, seventy-three million, nine hundred nineteen thousand, six hundred forty-nine".