649772061538 has 4 divisors (see below), whose sum is σ = 974658092310. Its totient is φ = 324886030768.

The previous prime is 649772061529. The next prime is 649772061581. The reversal of 649772061538 is 835160277946.

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

It can be written as a sum of positive squares in only one way, i.e., 549699167889 + 100072893649 = 741417^2 + 316343^2 .

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 162443015383 + ... + 162443015386.

It is a 1-persistent number, because it is pandigital, but 2⋅649772061538 = 1299544123076 is not.

Almost surely, 2^649772061538 is an apocalyptic number.

649772061538 is a deficient number, since it is larger than the sum of its proper divisors (324886030772).

649772061538 is a wasteful number, since it uses less digits than its factorization.

649772061538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324886030771.

The product of its (nonzero) digits is 15240960, while the sum is 58.

The spelling of 649772061538 in words is "six hundred forty-nine billion, seven hundred seventy-two million, sixty-one thousand, five hundred thirty-eight".