21204103453 has 8 divisors (see below), whose sum is σ = 22953508088. Its totient is φ = 19471601664.

The previous prime is 21204103421. The next prime is 21204103477. The reversal of 21204103453 is 35430140212.

It can be written as a sum of positive squares in 4 ways, for example, as 1131447769 + 20072655684 = 33637^2 + 141678^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21204103453 - 2⁵ = 21204103421 is a prime.

It is a super-2 number, since 2×21204103453² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21204109453) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4223100 + ... + 4228117.

It is an arithmetic number, because the mean of its divisors is an integer number (2869188511).

Almost surely, 2^21204103453 is an apocalyptic number.

It is an amenable number.

21204103453 is a deficient number, since it is larger than the sum of its proper divisors (1749404635).

21204103453 is a wasteful number, since it uses less digits than its factorization.

21204103453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8451423.

The product of its (nonzero) digits is 2880, while the sum is 25.

Adding to 21204103453 its reverse (35430140212), we get a palindrome (56634243665).

The spelling of 21204103453 in words is "twenty-one billion, two hundred four million, one hundred three thousand, four hundred fifty-three".