649751971 has 24 divisors (see below), whose sum is σ = 746468352. Its totient is φ = 564471600.

The previous prime is 649751959. The next prime is 649751981. The reversal of 649751971 is 179157946.

It is not a de Polignac number, because 649751971 - 2¹⁷ = 649620899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (649751981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 310290 + ... + 312376.

It is an arithmetic number, because the mean of its divisors is an integer number (31102848).

Almost surely, 2^649751971 is an apocalyptic number.

649751971 is a deficient number, since it is larger than the sum of its proper divisors (96716381).

649751971 is a wasteful number, since it uses less digits than its factorization.

649751971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2223 (or 2212 counting only the distinct ones).

The product of its digits is 476280, while the sum is 49.

The square root of 649751971 is about 25490.2328549584. The cubic root of 649751971 is about 866.1289105958.

The spelling of 649751971 in words is "six hundred forty-nine million, seven hundred fifty-one thousand, nine hundred seventy-one".