21405545203 has 8 divisors (see below), whose sum is σ = 24476598272. Its totient is φ = 18337771656.

The previous prime is 21405545201. The next prime is 21405545267. The reversal of 21405545203 is 30254550412.

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

It is a cyclic number.

It is not a de Polignac number, because 21405545203 - 2¹ = 21405545201 is a prime.

It is a super-2 number, since 2×21405545203² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21405545201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 805875 + ... + 832012.

It is an arithmetic number, because the mean of its divisors is an integer number (3059574784).

Almost surely, 2^21405545203 is an apocalyptic number.

21405545203 is a deficient number, since it is larger than the sum of its proper divisors (3071053069).

21405545203 is a wasteful number, since it uses less digits than its factorization.

21405545203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1639761.

The product of its (nonzero) digits is 24000, while the sum is 31.

The spelling of 21405545203 in words is "twenty-one billion, four hundred five million, five hundred forty-five thousand, two hundred three".