6400090 has 8 divisors (see below), whose sum is σ = 11520180. Its totient is φ = 2560032.

The previous prime is 6400033. The next prime is 6400091. The reversal of 6400090 is 900046.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 5774409 + 625681 = 2403^2 + 791^2 .

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

It is a super-2 number, since 2×6400090² = 81922304016200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6400091) 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, 319995 + ... + 320014.

Almost surely, 2^6400090 is an apocalyptic number.

6400090 is a deficient number, since it is larger than the sum of its proper divisors (5120090).

6400090 is a wasteful number, since it uses less digits than its factorization.

6400090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 640016.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 6400090 is about 2529.8399158840. The cubic root of 6400090 is about 185.6644236383.

It can be divided in two parts, 64000 and 90, that multiplied together give a square (5760000 = 2400²).

The spelling of 6400090 in words is "six million, four hundred thousand, ninety".