20121177792 has 112 divisors (see below), whose sum is σ = 55708795872. Its totient is φ = 6402539520.

The previous prime is 20121177779. The next prime is 20121177809. The reversal of 20121177792 is 29777112102.

It is a super-3 number, since 3×20121177792³ (a number of 32 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 20121177792.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 349792 + ... + 403232.

Almost surely, 2^20121177792 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20121177792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27854397936).

20121177792 is an abundant number, since it is smaller than the sum of its proper divisors (35587618080).

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

20121177792 is a wasteful number, since it uses less digits than its factorization.

20121177792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53546 (or 53536 counting only the distinct ones).

The product of its (nonzero) digits is 24696, while the sum is 39.

Adding to 20121177792 its reverse (29777112102), we get a palindrome (49898289894).

The spelling of 20121177792 in words is "twenty billion, one hundred twenty-one million, one hundred seventy-seven thousand, seven hundred ninety-two".