20719157 has 2 divisors, whose sum is σ = 20719158. Its totient is φ = 20719156.

The previous prime is 20719121. The next prime is 20719169. The reversal of 20719157 is 75191702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19989841 + 729316 = 4471^2 + 854^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20719157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20719117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10359578 + 10359579.

It is an arithmetic number, because the mean of its divisors is an integer number (10359579).

Almost surely, 2^20719157 is an apocalyptic number.

It is an amenable number.

20719157 is a deficient number, since it is larger than the sum of its proper divisors (1).

20719157 is an equidigital number, since it uses as much as digits as its factorization.

20719157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4410, while the sum is 32.

The square root of 20719157 is about 4551.8300715207. The cubic root of 20719157 is about 274.6570137198.

The spelling of 20719157 in words is "twenty million, seven hundred nineteen thousand, one hundred fifty-seven".