21002553204245 has 8 divisors (see below), whose sum is σ = 25204632564384. Its totient is φ = 16800996750544.

The previous prime is 21002553204209. The next prime is 21002553204287. The reversal of 21002553204245 is 54240235520012.

It is a happy number.

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 21002553204245 - 2¹⁰ = 21002553203221 is a prime.

It is a super-2 number, since 2×21002553204245² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 130638239 + ... + 130798908.

It is an arithmetic number, because the mean of its divisors is an integer number (3150579070548).

Almost surely, 2^{21002553204245} is an apocalyptic number.

It is an amenable number.

21002553204245 is a deficient number, since it is larger than the sum of its proper divisors (4202079360139).

21002553204245 is a wasteful number, since it uses less digits than its factorization.

21002553204245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261453219.

The product of its (nonzero) digits is 96000, while the sum is 35.

Adding to 21002553204245 its reverse (54240235520012), we get a palindrome (75242788724257).

The spelling of 21002553204245 in words is "twenty-one trillion, two billion, five hundred fifty-three million, two hundred four thousand, two hundred forty-five".