20497387 has 2 divisors, whose sum is σ = 20497388. Its totient is φ = 20497386.

The previous prime is 20497363. The next prime is 20497391. The reversal of 20497387 is 78379402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20497387 - 2¹¹ = 20495339 is a prime.

It is not a weakly prime, because it can be changed into another prime (20497307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10248693 + 10248694.

It is an arithmetic number, because the mean of its divisors is an integer number (10248694).

Almost surely, 2^20497387 is an apocalyptic number.

20497387 is a deficient number, since it is larger than the sum of its proper divisors (1).

20497387 is an equidigital number, since it uses as much as digits as its factorization.

20497387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84672, while the sum is 40.

The square root of 20497387 is about 4527.4040022954. The cubic root of 20497387 is about 273.6735549631.

The spelling of 20497387 in words is "twenty million, four hundred ninety-seven thousand, three hundred eighty-seven".