640520146 has 16 divisors (see below), whose sum is σ = 1145775744. Its totient is φ = 262573344.

The previous prime is 640520143. The next prime is 640520149. The reversal of 640520146 is 641025046.

It is an interprime number because it is at equal distance from previous prime (640520143) and next prime (640520149).

It is a super-2 number, since 2×640520146² = 820532114863722632, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (640520141) 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, 994275 + ... + 994918.

It is an arithmetic number, because the mean of its divisors is an integer number (71610984).

Almost surely, 2^640520146 is an apocalyptic number.

640520146 is a deficient number, since it is larger than the sum of its proper divisors (505255598).

640520146 is a wasteful number, since it uses less digits than its factorization.

640520146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1989225.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 640520146 is about 25308.4994813995. The cubic root of 640520146 is about 862.0072754162.

The spelling of 640520146 in words is "six hundred forty million, five hundred twenty thousand, one hundred forty-six".