20453921 has 2 divisors, whose sum is σ = 20453922. Its totient is φ = 20453920.

The previous prime is 20453887. The next prime is 20453987. The reversal of 20453921 is 12935402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13104400 + 7349521 = 3620^2 + 2711^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20453921 is a prime.

It is not a weakly prime, because it can be changed into another prime (20453821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10226960 + 10226961.

It is an arithmetic number, because the mean of its divisors is an integer number (10226961).

Almost surely, 2^20453921 is an apocalyptic number.

It is an amenable number.

20453921 is a deficient number, since it is larger than the sum of its proper divisors (1).

20453921 is an equidigital number, since it uses as much as digits as its factorization.

20453921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 20453921 is about 4522.6011320920. The cubic root of 20453921 is about 273.4799707266.

The spelling of 20453921 in words is "twenty million, four hundred fifty-three thousand, nine hundred twenty-one".