21421431203 has 4 divisors (see below), whose sum is σ = 21692588640. Its totient is φ = 21150273768.

The previous prime is 21421431127. The next prime is 21421431223. The reversal of 21421431203 is 30213412412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21421431203 - 2¹⁸ = 21421169059 is a prime.

It is a super-3 number, since 3×21421431203³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21421431223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 135578600 + ... + 135578757.

It is an arithmetic number, because the mean of its divisors is an integer number (5423147160).

Almost surely, 2^21421431203 is an apocalyptic number.

21421431203 is a deficient number, since it is larger than the sum of its proper divisors (271157437).

21421431203 is an equidigital number, since it uses as much as digits as its factorization.

21421431203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271157436.

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 21421431203 its reverse (30213412412), we get a palindrome (51634843615).

The spelling of 21421431203 in words is "twenty-one billion, four hundred twenty-one million, four hundred thirty-one thousand, two hundred three".