20748121 has 2 divisors, whose sum is σ = 20748122. Its totient is φ = 20748120.

The previous prime is 20748097. The next prime is 20748151. The reversal of 20748121 is 12184702.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12110400 + 8637721 = 3480^2 + 2939^2 .

It is a cyclic number.

It is not a de Polignac number, because 20748121 - 2¹⁷ = 20617049 is a prime.

It is not a weakly prime, because it can be changed into another prime (20748151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10374060 + 10374061.

It is an arithmetic number, because the mean of its divisors is an integer number (10374061).

Almost surely, 2^20748121 is an apocalyptic number.

It is an amenable number.

20748121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20748121 is an equidigital number, since it uses as much as digits as its factorization.

20748121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 20748121 is about 4555.0105378583. The cubic root of 20748121 is about 274.7849381924.

The spelling of 20748121 in words is "twenty million, seven hundred forty-eight thousand, one hundred twenty-one".