21611771137376 has 72 divisors (see below), whose sum is σ = 50050936991160. Its totient is φ = 9158118047232.

The previous prime is 21611771137339. The next prime is 21611771137457. The reversal of 21611771137376 is 67373117711612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 77293130 + ... + 77572233.

It is an arithmetic number, because the mean of its divisors is an integer number (695151902655).

Almost surely, 2^{21611771137376} is an apocalyptic number.

It is an amenable number.

21611771137376 is an abundant number, since it is smaller than the sum of its proper divisors (28439165853784).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21611771137376 is a wasteful number, since it uses less digits than its factorization.

21611771137376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154865476 (or 154865461 counting only the distinct ones).

The product of its digits is 1555848, while the sum is 53.

Adding to 21611771137376 its reverse (67373117711612), we get a palindrome (88984888848988).

The spelling of 21611771137376 in words is "twenty-one trillion, six hundred eleven billion, seven hundred seventy-one million, one hundred thirty-seven thousand, three hundred seventy-six".