21012312003 has 16 divisors (see below), whose sum is σ = 28145698560. Its totient is φ = 13943710496.

The previous prime is 21012311959. The next prime is 21012312011. The reversal of 21012312003 is 30021321012.

It is a cyclic number.

It is not a de Polignac number, because 21012312003 - 2²² = 21008117699 is a prime.

It is a super-2 number, since 2×21012312003² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21012312073) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 582376 + ... + 617402.

It is an arithmetic number, because the mean of its divisors is an integer number (1759106160).

Almost surely, 2^21012312003 is an apocalyptic number.

21012312003 is a deficient number, since it is larger than the sum of its proper divisors (7133386557).

21012312003 is a wasteful number, since it uses less digits than its factorization.

21012312003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35946.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21012312003 its reverse (30021321012), we get a palindrome (51033633015).

Subtracting 21012312003 from its reverse (30021321012), we obtain a palindrome (9009009009).

The spelling of 21012312003 in words is "twenty-one billion, twelve million, three hundred twelve thousand, three".