21433403021 has 16 divisors (see below), whose sum is σ = 22998528000. Its totient is φ = 19902475008.

The previous prime is 21433402951. The next prime is 21433403023. The reversal of 21433403021 is 12030433412.

It is a de Polignac number, because none of the positive numbers 2^k-21433403021 is a prime.

It is a super-2 number, since 2×21433403021² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21433403023) 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, 2075156 + ... + 2085458.

It is an arithmetic number, because the mean of its divisors is an integer number (1437408000).

Almost surely, 2^21433403021 is an apocalyptic number.

It is an amenable number.

21433403021 is a deficient number, since it is larger than the sum of its proper divisors (1565124979).

21433403021 is a wasteful number, since it uses less digits than its factorization.

21433403021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11948.

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 21433403021 its reverse (12030433412), we get a palindrome (33463836433).

The spelling of 21433403021 in words is "twenty-one billion, four hundred thirty-three million, four hundred three thousand, twenty-one".