64791890 has 16 divisors (see below), whose sum is σ = 119470680. Its totient is φ = 25284480.

The previous prime is 64791877. The next prime is 64791899. The reversal of 64791890 is 9819746.

It can be written as a sum of positive squares in 4 ways, for example, as 47210641 + 17581249 = 6871^2 + 4193^2 .

It is not an unprimeable number, because it can be changed into a prime (64791899) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78605 + ... + 79424.

Almost surely, 2^64791890 is an apocalyptic number.

64791890 is a deficient number, since it is larger than the sum of its proper divisors (54678790).

64791890 is a wasteful number, since it uses less digits than its factorization.

64791890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158077.

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 64791890 is about 8049.3409668121. The cubic root of 64791890 is about 401.6430128649.

The spelling of 64791890 in words is "sixty-four million, seven hundred ninety-one thousand, eight hundred ninety".