21115433077 has 16 divisors (see below), whose sum is σ = 22625056000. Its totient is φ = 19648272384.

The previous prime is 21115432997. The next prime is 21115433111. The reversal of 21115433077 is 77033451112.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21115433077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115439077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 253249 + ... + 326137.

It is an arithmetic number, because the mean of its divisors is an integer number (1414066000).

Almost surely, 2^21115433077 is an apocalyptic number.

It is an amenable number.

21115433077 is a deficient number, since it is larger than the sum of its proper divisors (1509622923).

21115433077 is a wasteful number, since it uses less digits than its factorization.

21115433077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73180.

The product of its (nonzero) digits is 17640, while the sum is 34.

Adding to 21115433077 its reverse (77033451112), we get a palindrome (98148884189).

The spelling of 21115433077 in words is "twenty-one billion, one hundred fifteen million, four hundred thirty-three thousand, seventy-seven".