21115334506461 has 32 divisors (see below), whose sum is σ = 30473487249408. Its totient is φ = 12928195438080.

The previous prime is 21115334506439. The next prime is 21115334506471. The reversal of 21115334506461 is 16460543351112.

It is not a de Polignac number, because 21115334506461 - 2¹⁵ = 21115334473693 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115334506471) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4802020 + ... + 8080226.

It is an arithmetic number, because the mean of its divisors is an integer number (952296476544).

Almost surely, 2^{21115334506461} is an apocalyptic number.

It is an amenable number.

21115334506461 is a deficient number, since it is larger than the sum of its proper divisors (9358152742947).

21115334506461 is a wasteful number, since it uses less digits than its factorization.

21115334506461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3279061.

The product of its (nonzero) digits is 259200, while the sum is 42.

Adding to 21115334506461 its reverse (16460543351112), we get a palindrome (37575877857573).

The spelling of 21115334506461 in words is "twenty-one trillion, one hundred fifteen billion, three hundred thirty-four million, five hundred six thousand, four hundred sixty-one".