215901982551 has 4 divisors (see below), whose sum is σ = 287869310072. Its totient is φ = 143934655032.

The previous prime is 215901982531. The next prime is 215901982567. The reversal of 215901982551 is 155289109512.

215901982551 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 215901982551 - 2⁵ = 215901982519 is a prime.

It is a super-2 number, since 2×215901982551² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 215901982551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215901982501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35983663756 + ... + 35983663761.

It is an arithmetic number, because the mean of its divisors is an integer number (71967327518).

Almost surely, 2^215901982551 is an apocalyptic number.

215901982551 is a deficient number, since it is larger than the sum of its proper divisors (71967327521).

215901982551 is an equidigital number, since it uses as much as digits as its factorization.

215901982551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71967327520.

The product of its (nonzero) digits is 324000, while the sum is 48.

The spelling of 215901982551 in words is "two hundred fifteen billion, nine hundred one million, nine hundred eighty-two thousand, five hundred fifty-one".