215688001 has 8 divisors (see below), whose sum is σ = 218642600. Its totient is φ = 212751360.

The previous prime is 215687977. The next prime is 215688007. The reversal of 215688001 is 100886512.

It can be written as a sum of positive squares in 4 ways, for example, as 39992976 + 175695025 = 6324^2 + 13255^2 .

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

It is a 7-Lehmer number, since φ(215688001) divides (215688001-1)⁷.

It is a cyclic number.

It is not a de Polignac number, because 215688001 - 2¹⁵ = 215655233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215688007) 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 7 ways as a sum of consecutive naturals, for example, 20641 + ... + 29281.

It is an arithmetic number, because the mean of its divisors is an integer number (27330325).

Almost surely, 2^215688001 is an apocalyptic number.

It is an amenable number.

215688001 is a deficient number, since it is larger than the sum of its proper divisors (2954599).

215688001 is a wasteful number, since it uses less digits than its factorization.

It is an anagram of its base 11 representation: 215688001 = (100828651)₁₁.

215688001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8979.

The product of its (nonzero) digits is 3840, while the sum is 31.

The square root of 215688001 is about 14686.3201994237. The cubic root of 215688001 is about 599.7109728316.

The spelling of 215688001 in words is "two hundred fifteen million, six hundred eighty-eight thousand, one".