21421433253 has 16 divisors (see below), whose sum is σ = 32991299136. Its totient is φ = 12218999040.

The previous prime is 21421433213. The next prime is 21421433269. The reversal of 21421433253 is 35233412412.

It is not a de Polignac number, because 21421433253 - 2⁸ = 21421432997 is a prime.

It is a super-2 number, since 2×21421433253² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21421433253.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21421433213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19091626 + ... + 19092747.

It is an arithmetic number, because the mean of its divisors is an integer number (2061956196).

Almost surely, 2^21421433253 is an apocalyptic number.

It is an amenable number.

21421433253 is a deficient number, since it is larger than the sum of its proper divisors (11569865883).

21421433253 is a wasteful number, since it uses less digits than its factorization.

21421433253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38184404.

The product of its digits is 17280, while the sum is 30.

Adding to 21421433253 its reverse (35233412412), we get a palindrome (56654845665).

The spelling of 21421433253 in words is "twenty-one billion, four hundred twenty-one million, four hundred thirty-three thousand, two hundred fifty-three".