20356397 has 2 divisors, whose sum is σ = 20356398. Its totient is φ = 20356396.

The previous prime is 20356393. The next prime is 20356421. The reversal of 20356397 is 79365302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13060996 + 7295401 = 3614^2 + 2701^2 .

It is a cyclic number.

It is not a de Polignac number, because 20356397 - 2² = 20356393 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20356393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10178198 + 10178199.

It is an arithmetic number, because the mean of its divisors is an integer number (10178199).

Almost surely, 2^20356397 is an apocalyptic number.

It is an amenable number.

20356397 is a deficient number, since it is larger than the sum of its proper divisors (1).

20356397 is an equidigital number, since it uses as much as digits as its factorization.

20356397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34020, while the sum is 35.

The square root of 20356397 is about 4511.8064009884. The cubic root of 20356397 is about 273.0446285728.

The spelling of 20356397 in words is "twenty million, three hundred fifty-six thousand, three hundred ninety-seven".