649121287 has 4 divisors (see below), whose sum is σ = 650086480. Its totient is φ = 648156096.

The previous prime is 649121281. The next prime is 649121299. The reversal of 649121287 is 782121946.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 649121287 - 2³ = 649121279 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649121281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 481587 + ... + 482932.

It is an arithmetic number, because the mean of its divisors is an integer number (162521620).

Almost surely, 2^649121287 is an apocalyptic number.

649121287 is a deficient number, since it is larger than the sum of its proper divisors (965193).

649121287 is an equidigital number, since it uses as much as digits as its factorization.

649121287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 965192.

The product of its digits is 48384, while the sum is 40.

The square root of 649121287 is about 25477.8587601078. The cubic root of 649121287 is about 865.8485828674.

The spelling of 649121287 in words is "six hundred forty-nine million, one hundred twenty-one thousand, two hundred eighty-seven".