20021231233453 has 4 divisors (see below), whose sum is σ = 21074980245760. Its totient is φ = 18967482221148.

The previous prime is 20021231233439. The next prime is 20021231233463. The reversal of 20021231233453 is 35433213212002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20021231233453 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 (20021231233463) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 526874506125 + ... + 526874506162.

It is an arithmetic number, because the mean of its divisors is an integer number (5268745061440).

Almost surely, 2^{20021231233453} is an apocalyptic number.

It is an amenable number.

20021231233453 is a deficient number, since it is larger than the sum of its proper divisors (1053749012307).

20021231233453 is a wasteful number, since it uses less digits than its factorization.

20021231233453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1053749012306.

The product of its (nonzero) digits is 25920, while the sum is 31.

Adding to 20021231233453 its reverse (35433213212002), we get a palindrome (55454444445455).

The spelling of 20021231233453 in words is "twenty trillion, twenty-one billion, two hundred thirty-one million, two hundred thirty-three thousand, four hundred fifty-three".