21203033453 has 4 divisors (see below), whose sum is σ = 24232038240. Its totient is φ = 18174028668.

The previous prime is 21203033399. The next prime is 21203033477. The reversal of 21203033453 is 35433030212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21203033453 - 2²² = 21198839149 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203033153) 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, 1514502383 + ... + 1514502396.

It is an arithmetic number, because the mean of its divisors is an integer number (6058009560).

Almost surely, 2^21203033453 is an apocalyptic number.

It is an amenable number.

21203033453 is a deficient number, since it is larger than the sum of its proper divisors (3029004787).

21203033453 is an equidigital number, since it uses as much as digits as its factorization.

21203033453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3029004786.

The product of its (nonzero) digits is 6480, while the sum is 26.

Adding to 21203033453 its reverse (35433030212), we get a palindrome (56636063665).

The spelling of 21203033453 in words is "twenty-one billion, two hundred three million, thirty-three thousand, four hundred fifty-three".