215551828028281 has 4 divisors (see below), whose sum is σ = 215623416150864. Its totient is φ = 215480239905700.

The previous prime is 215551828028279. The next prime is 215551828028287. The reversal of 215551828028281 is 182820828155512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 215551828028281 - 2¹ = 215551828028279 is a prime.

It is a super-2 number, since 2×215551828028281² (a number of 29 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215551828028287) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35794056775 + ... + 35794062796.

It is an arithmetic number, because the mean of its divisors is an integer number (53905854037716).

Almost surely, 2^{215551828028281} is an apocalyptic number.

It is an amenable number.

215551828028281 is a deficient number, since it is larger than the sum of its proper divisors (71588122583).

215551828028281 is an equidigital number, since it uses as much as digits as its factorization.

215551828028281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71588122582.

The product of its (nonzero) digits is 8192000, while the sum is 58.

The spelling of 215551828028281 in words is "two hundred fifteen trillion, five hundred fifty-one billion, eight hundred twenty-eight million, twenty-eight thousand, two hundred eighty-one".