21021440403 has 16 divisors (see below), whose sum is σ = 28566258336. Its totient is φ = 13745621760.

The previous prime is 21021440371. The next prime is 21021440413. The reversal of 21021440403 is 30404412012.

It is not a de Polignac number, because 21021440403 - 2⁵ = 21021440371 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21021440403.

It is not an unprimeable number, because it can be changed into a prime (21021440413) 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, 544351 + ... + 581687.

It is an arithmetic number, because the mean of its divisors is an integer number (1785391146).

Almost surely, 2^21021440403 is an apocalyptic number.

21021440403 is a deficient number, since it is larger than the sum of its proper divisors (7544817933).

21021440403 is a wasteful number, since it uses less digits than its factorization.

21021440403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40934.

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21021440403 its reverse (30404412012), we get a palindrome (51425852415).

The spelling of 21021440403 in words is "twenty-one billion, twenty-one million, four hundred forty thousand, four hundred three".