640215213 has 16 divisors (see below), whose sum is σ = 931694400. Its totient is φ = 387812480.

The previous prime is 640215197. The next prime is 640215221. The reversal of 640215213 is 312512046.

It is not a de Polignac number, because 640215213 - 2⁴ = 640215197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640215293) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86503 + ... + 93611.

It is an arithmetic number, because the mean of its divisors is an integer number (58230900).

Almost surely, 2^640215213 is an apocalyptic number.

It is an amenable number.

640215213 is a deficient number, since it is larger than the sum of its proper divisors (291479187).

640215213 is a wasteful number, since it uses less digits than its factorization.

640215213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9852.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 640215213 is about 25302.4744442120. The cubic root of 640215213 is about 861.8704615108.

Adding to 640215213 its reverse (312512046), we get a palindrome (952727259).

The spelling of 640215213 in words is "six hundred forty million, two hundred fifteen thousand, two hundred thirteen".