20277281 has 2 divisors, whose sum is σ = 20277282. Its totient is φ = 20277280.

The previous prime is 20277269. The next prime is 20277287. The reversal of 20277281 is 18277202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19936225 + 341056 = 4465^2 + 584^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20277281 is a prime.

It is a super-2 number, since 2×20277281² = 822336249505922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20277287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10138640 + 10138641.

It is an arithmetic number, because the mean of its divisors is an integer number (10138641).

Almost surely, 2^20277281 is an apocalyptic number.

It is an amenable number.

20277281 is a deficient number, since it is larger than the sum of its proper divisors (1).

20277281 is an equidigital number, since it uses as much as digits as its factorization.

20277281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 20277281 is about 4503.0302019862. The cubic root of 20277281 is about 272.6904361393.

The spelling of 20277281 in words is "twenty million, two hundred seventy-seven thousand, two hundred eighty-one".