20257121976 has 128 divisors (see below), whose sum is σ = 62610616320. Its totient is φ = 5318452224.

The previous prime is 20257121939. The next prime is 20257121977. The reversal of 20257121976 is 67912175202.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20257121977) 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 31 ways as a sum of consecutive naturals, for example, 466236 + ... + 507828.

It is an arithmetic number, because the mean of its divisors is an integer number (489145440).

Almost surely, 2^20257121976 is an apocalyptic number.

20257121976 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20257121976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31305308160).

20257121976 is an abundant number, since it is smaller than the sum of its proper divisors (42353494344).

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

20257121976 is a wasteful number, since it uses less digits than its factorization.

20257121976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41845 (or 41841 counting only the distinct ones).

The product of its (nonzero) digits is 105840, while the sum is 42.

The spelling of 20257121976 in words is "twenty billion, two hundred fifty-seven million, one hundred twenty-one thousand, nine hundred seventy-six".