20719121 has 2 divisors, whose sum is σ = 20719122. Its totient is φ = 20719120.

The previous prime is 20719117. The next prime is 20719157. The reversal of 20719121 is 12191702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18800896 + 1918225 = 4336^2 + 1385^2 .

It is a cyclic number.

It is not a de Polignac number, because 20719121 - 2² = 20719117 is a prime.

It is a Chen prime.

It is equal to p_1313339 and since 20719121 and 1313339 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (20719921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10359560 + 10359561.

It is an arithmetic number, because the mean of its divisors is an integer number (10359561).

Almost surely, 2^20719121 is an apocalyptic number.

It is an amenable number.

20719121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20719121 is an equidigital number, since it uses as much as digits as its factorization.

20719121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 252, while the sum is 23.

The square root of 20719121 is about 4551.8261170655. The cubic root of 20719121 is about 274.6568546455.

The spelling of 20719121 in words is "twenty million, seven hundred nineteen thousand, one hundred twenty-one".