21101021424433 has 4 divisors (see below), whose sum is σ = 21101031517428. Its totient is φ = 21101011331440.

The previous prime is 21101021424347. The next prime is 21101021424437. The reversal of 21101021424433 is 33442412010112.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 13986276071329 + 7114745353104 = 3739823^2 + 2667348^2 .

It is a cyclic number.

It is not a de Polignac number, because 21101021424433 - 2⁴¹ = 18901998168881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21101021424437) 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, 611038 + ... + 6524983.

It is an arithmetic number, because the mean of its divisors is an integer number (5275257879357).

Almost surely, 2^{21101021424433} is an apocalyptic number.

It is an amenable number.

21101021424433 is a deficient number, since it is larger than the sum of its proper divisors (10092995).

21101021424433 is an equidigital number, since it uses as much as digits as its factorization.

21101021424433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10092994.

The product of its (nonzero) digits is 4608, while the sum is 28.

Adding to 21101021424433 its reverse (33442412010112), we get a palindrome (54543433434545).

The spelling of 21101021424433 in words is "twenty-one trillion, one hundred one billion, twenty-one million, four hundred twenty-four thousand, four hundred thirty-three".