215020840 has 16 divisors (see below), whose sum is σ = 483796980. Its totient is φ = 86008320.

The previous prime is 215020831. The next prime is 215020847. The reversal of 215020840 is 48020512.

It can be written as a sum of positive squares in 2 ways, for example, as 214505316 + 515524 = 14646^2 + 718^2 .

It is not an unprimeable number, because it can be changed into a prime (215020847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2687721 + ... + 2687800.

Almost surely, 2^215020840 is an apocalyptic number.

215020840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215020840 is an abundant number, since it is smaller than the sum of its proper divisors (268776140).

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

215020840 is a wasteful number, since it uses less digits than its factorization.

215020840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5375532 (or 5375528 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 215020840 is about 14663.5889194972. The cubic root of 215020840 is about 599.0919969476.

The spelling of 215020840 in words is "two hundred fifteen million, twenty thousand, eight hundred forty".