651181 has 2 divisors, whose sum is σ = 651182. Its totient is φ = 651180.

The previous prime is 651179. The next prime is 651191. The reversal of 651181 is 181156.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 366025 + 285156 = 605^2 + 534^2 .

It is a cyclic number.

It is not a de Polignac number, because 651181 - 2¹ = 651179 is a prime.

It is a super-2 number, since 2×651181² = 848073389522, which contains 22 as substring.

Together with 651179, it forms a pair of twin primes.

It is an Ulam number.

651181 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (651191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325590 + 325591.

It is an arithmetic number, because the mean of its divisors is an integer number (325591).

2⁶⁵¹¹⁸¹ is an apocalyptic number.

It is an amenable number.

651181 is a deficient number, since it is larger than the sum of its proper divisors (1).

651181 is an equidigital number, since it uses as much as digits as its factorization.

651181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 240, while the sum is 22.

The square root of 651181 is about 806.9578675495. The cubic root of 651181 is about 86.6763417864.

The spelling of 651181 in words is "six hundred fifty-one thousand, one hundred eighty-one".