649252381 has 2 divisors, whose sum is σ = 649252382. Its totient is φ = 649252380.

The previous prime is 649252369. The next prime is 649252397. The reversal of 649252381 is 183252946.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 549152356 + 100100025 = 23434^2 + 10005^2 .

It is a cyclic number.

It is not a de Polignac number, because 649252381 - 2¹¹ = 649250333 is a prime.

It is a super-2 number, since 2×649252381² = 843057308468338322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (649252301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324626190 + 324626191.

It is an arithmetic number, because the mean of its divisors is an integer number (324626191).

Almost surely, 2^649252381 is an apocalyptic number.

It is an amenable number.

649252381 is a deficient number, since it is larger than the sum of its proper divisors (1).

649252381 is an equidigital number, since it uses as much as digits as its factorization.

649252381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 40.

The square root of 649252381 is about 25480.4313346537. The cubic root of 649252381 is about 865.9068667434.

The spelling of 649252381 in words is "six hundred forty-nine million, two hundred fifty-two thousand, three hundred eighty-one".