21102021003 has 16 divisors (see below), whose sum is σ = 32157866240. Its totient is φ = 12057395616.

The previous prime is 21102020987. The next prime is 21102021019. The reversal of 21102021003 is 30012020112.

It is an interprime number because it is at equal distance from previous prime (21102020987) and next prime (21102021019).

It is not a de Polignac number, because 21102021003 - 2⁴ = 21102020987 is a prime.

It is a super-2 number, since 2×21102021003² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21102021003.

It is not an unprimeable number, because it can be changed into a prime (21102021023) 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, 336276 + ... + 394062.

It is an arithmetic number, because the mean of its divisors is an integer number (2009866640).

Almost surely, 2^21102021003 is an apocalyptic number.

21102021003 is a deficient number, since it is larger than the sum of its proper divisors (11055845237).

21102021003 is a wasteful number, since it uses less digits than its factorization.

21102021003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75186.

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21102021003 its reverse (30012020112), we get a palindrome (51114041115).

The spelling of 21102021003 in words is "twenty-one billion, one hundred two million, twenty-one thousand, three".