21115503245554 has 16 divisors (see below), whose sum is σ = 31781693549592. Its totient is φ = 10521606164608.

The previous prime is 21115503245549. The next prime is 21115503245591. The reversal of 21115503245554 is 45554230551112.

It can be written as a sum of positive squares in 4 ways, for example, as 21090385750329 + 25117495225 = 4592427^2 + 158485^2 .

It is a super-3 number, since 3×21115503245554³ (a number of 41 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21115503245554.

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, 95239092 + ... + 95460544.

Almost surely, 2^{21115503245554} is an apocalyptic number.

21115503245554 is a deficient number, since it is larger than the sum of its proper divisors (10666190304038).

21115503245554 is a wasteful number, since it uses less digits than its factorization.

21115503245554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384461.

The product of its (nonzero) digits is 600000, while the sum is 43.

Adding to 21115503245554 its reverse (45554230551112), we get a palindrome (66669733796666).

The spelling of 21115503245554 in words is "twenty-one trillion, one hundred fifteen billion, five hundred three million, two hundred forty-five thousand, five hundred fifty-four".