20021021201749 has 2 divisors, whose sum is σ = 20021021201750. Its totient is φ = 20021021201748.

The previous prime is 20021021201743. The next prime is 20021021201821. The reversal of 20021021201749 is 94710212012002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12674183846724 + 7346837355025 = 3560082^2 + 2710505^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021021201749 - 2³⁵ = 19986661463381 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20021021201749.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20021021201743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010510600874 + 10010510600875.

It is an arithmetic number, because the mean of its divisors is an integer number (10010510600875).

Almost surely, 2^{20021021201749} is an apocalyptic number.

It is an amenable number.

20021021201749 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021021201749 is an equidigital number, since it uses as much as digits as its factorization.

20021021201749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 31.

The spelling of 20021021201749 in words is "twenty trillion, twenty-one billion, twenty-one million, two hundred one thousand, seven hundred forty-nine".