649173890 has 8 divisors (see below), whose sum is σ = 1168513020. Its totient is φ = 259669552.

The previous prime is 649173887. The next prime is 649173901. The reversal of 649173890 is 98371946.

It can be written as a sum of positive squares in 2 ways, for example, as 604028929 + 45144961 = 24577^2 + 6719^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32458685 + ... + 32458704.

Almost surely, 2^649173890 is an apocalyptic number.

649173890 is a deficient number, since it is larger than the sum of its proper divisors (519339130).

649173890 is a wasteful number, since it uses less digits than its factorization.

649173890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64917396.

The product of its (nonzero) digits is 326592, while the sum is 47.

The square root of 649173890 is about 25478.8910669205. The cubic root of 649173890 is about 865.8719708966.

The spelling of 649173890 in words is "six hundred forty-nine million, one hundred seventy-three thousand, eight hundred ninety".