65371981 has 2 divisors, whose sum is σ = 65371982. Its totient is φ = 65371980.

The previous prime is 65371939. The next prime is 65371991. The reversal of 65371981 is 18917356.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50893956 + 14478025 = 7134^2 + 3805^2 .

It is a cyclic number.

It is not a de Polignac number, because 65371981 - 2¹³ = 65363789 is a prime.

It is a super-2 number, since 2×65371981² = 8546991799728722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65371991) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32685990 + 32685991.

It is an arithmetic number, because the mean of its divisors is an integer number (32685991).

Almost surely, 2^65371981 is an apocalyptic number.

It is an amenable number.

65371981 is a deficient number, since it is larger than the sum of its proper divisors (1).

65371981 is an equidigital number, since it uses as much as digits as its factorization.

65371981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45360, while the sum is 40.

The square root of 65371981 is about 8085.2941195729. The cubic root of 65371981 is about 402.8381089675.

The spelling of 65371981 in words is "sixty-five million, three hundred seventy-one thousand, nine hundred eighty-one".