21103503531 has 8 divisors (see below), whose sum is σ = 30696005184. Its totient is φ = 12790002120.

The previous prime is 21103503529. The next prime is 21103503539. The reversal of 21103503531 is 13530530112.

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

It is not a de Polignac number, because 21103503531 - 2¹ = 21103503529 is a prime.

It is a super-2 number, since 2×21103503531² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21103503539) 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, 319750021 + ... + 319750086.

It is an arithmetic number, because the mean of its divisors is an integer number (3837000648).

Almost surely, 2^21103503531 is an apocalyptic number.

21103503531 is a deficient number, since it is larger than the sum of its proper divisors (9592501653).

21103503531 is a wasteful number, since it uses less digits than its factorization.

21103503531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639500121.

The product of its (nonzero) digits is 1350, while the sum is 24.

The spelling of 21103503531 in words is "twenty-one billion, one hundred three million, five hundred three thousand, five hundred thirty-one".