21003773451 has 8 divisors (see below), whose sum is σ = 28009759440. Its totient is φ = 14000151552.

The previous prime is 21003773447. The next prime is 21003773471. The reversal of 21003773451 is 15437730012.

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

It is not a de Polignac number, because 21003773451 - 2² = 21003773447 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21003773431) 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, 570186 + ... + 605903.

It is an arithmetic number, because the mean of its divisors is an integer number (3501219930).

Almost surely, 2^21003773451 is an apocalyptic number.

21003773451 is a deficient number, since it is larger than the sum of its proper divisors (7005985989).

21003773451 is a wasteful number, since it uses less digits than its factorization.

21003773451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1182045.

The product of its (nonzero) digits is 17640, while the sum is 33.

The spelling of 21003773451 in words is "twenty-one billion, three million, seven hundred seventy-three thousand, four hundred fifty-one".