215432640 has 336 divisors, whose sum is σ = 811499520. Its totient is φ = 52254720.

The previous prime is 215432629. The next prime is 215432641. The reversal of 215432640 is 46234512.

215432640 is a `hidden beast` number, since 2 + 15 + 4 + 3 + 2 + 640 = 666.

It is a super-2 number, since 2×215432640² = 92822444754739200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215432641) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1696257 + ... + 1696383.

Almost surely, 2^215432640 is an apocalyptic number.

215432640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215432640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (405749760).

215432640 is an abundant number, since it is smaller than the sum of its proper divisors (596066880).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

215432640 is a wasteful number, since it uses less digits than its factorization.

215432640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200 (or 187 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 215432640 is about 14677.6237858858. The cubic root of 215432640 is about 599.4742060358.

The spelling of 215432640 in words is "two hundred fifteen million, four hundred thirty-two thousand, six hundred forty".