20011231110021 has 16 divisors (see below), whose sum is σ = 26873952060480. Its totient is φ = 13244667995520.

The previous prime is 20011231109999. The next prime is 20011231110041. The reversal of 20011231110021 is 12001113211002.

It is a de Polignac number, because none of the positive numbers 2^k-20011231110021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011231110041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36185131 + ... + 36733991.

It is an arithmetic number, because the mean of its divisors is an integer number (1679622003780).

Almost surely, 2^{20011231110021} is an apocalyptic number.

It is an amenable number.

20011231110021 is a deficient number, since it is larger than the sum of its proper divisors (6862720950459).

20011231110021 is a wasteful number, since it uses less digits than its factorization.

20011231110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 636436.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 20011231110021 its reverse (12001113211002), we get a palindrome (32012344321023).

The spelling of 20011231110021 in words is "twenty trillion, eleven billion, two hundred thirty-one million, one hundred ten thousand, twenty-one".