20269721 has 2 divisors, whose sum is σ = 20269722. Its totient is φ = 20269720.

The previous prime is 20269687. The next prime is 20269771. The reversal of 20269721 is 12796202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18181696 + 2088025 = 4264^2 + 1445^2 .

It is a cyclic number.

It is not a de Polignac number, because 20269721 - 2⁶ = 20269657 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20269771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10134860 + 10134861.

It is an arithmetic number, because the mean of its divisors is an integer number (10134861).

Almost surely, 2^20269721 is an apocalyptic number.

It is an amenable number.

20269721 is a deficient number, since it is larger than the sum of its proper divisors (1).

20269721 is an equidigital number, since it uses as much as digits as its factorization.

20269721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 20269721 is about 4502.1906889869. The cubic root of 20269721 is about 272.6565427727.

The spelling of 20269721 in words is "twenty million, two hundred sixty-nine thousand, seven hundred twenty-one".