649693281 has 4 divisors (see below), whose sum is σ = 866257712. Its totient is φ = 433128852.

The previous prime is 649693271. The next prime is 649693313. The reversal of 649693281 is 182396946.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 649693281 - 2¹⁴ = 649676897 is a prime.

It is a super-2 number, since 2×649693281² = 844202718753089922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 649693281.

It is not an unprimeable number, because it can be changed into a prime (649693271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108282211 + ... + 108282216.

It is an arithmetic number, because the mean of its divisors is an integer number (216564428).

Almost surely, 2^649693281 is an apocalyptic number.

It is an amenable number.

649693281 is a deficient number, since it is larger than the sum of its proper divisors (216564431).

649693281 is a wasteful number, since it uses less digits than its factorization.

649693281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216564430.

The product of its digits is 559872, while the sum is 48.

The square root of 649693281 is about 25489.0816036985. The cubic root of 649693281 is about 866.1028316002.

The spelling of 649693281 in words is "six hundred forty-nine million, six hundred ninety-three thousand, two hundred eighty-one".