65631281 has 2 divisors, whose sum is σ = 65631282. Its totient is φ = 65631280.

The previous prime is 65631253. The next prime is 65631299. The reversal of 65631281 is 18213656.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61465600 + 4165681 = 7840^2 + 2041^2 .

It is a cyclic number.

It is not a de Polignac number, because 65631281 - 2⁶ = 65631217 is a prime.

It is a super-2 number, since 2×65631281² = 8614930091401922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (65631211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32815640 + 32815641.

It is an arithmetic number, because the mean of its divisors is an integer number (32815641).

Almost surely, 2^65631281 is an apocalyptic number.

It is an amenable number.

65631281 is a deficient number, since it is larger than the sum of its proper divisors (1).

65631281 is an equidigital number, since it uses as much as digits as its factorization.

65631281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 32.

The square root of 65631281 is about 8101.3135354707. The cubic root of 65631281 is about 403.3700295976.

The spelling of 65631281 in words is "sixty-five million, six hundred thirty-one thousand, two hundred eighty-one".