221545540251 has 48 divisors (see below), whose sum is σ = 387711327744. Its totient is φ = 119005293312.

The previous prime is 221545540219. The next prime is 221545540273. The reversal of 221545540251 is 152045545122.

221545540251 is a `hidden beast` number, since 2 + 2 + 1 + 54 + 554 + 0 + 2 + 51 = 666.

221545540251 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221545540251 - 2⁵ = 221545540219 is a prime.

It is a super-2 number, since 2×221545540251² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221545540351) 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 47 ways as a sum of consecutive naturals, for example, 755760 + ... + 1007106.

It is an arithmetic number, because the mean of its divisors is an integer number (8077319328).

Almost surely, 2^221545540251 is an apocalyptic number.

221545540251 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

221545540251 is a deficient number, since it is larger than the sum of its proper divisors (166165787493).

221545540251 is a wasteful number, since it uses less digits than its factorization.

221545540251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252200 (or 252197 counting only the distinct ones).

The product of its (nonzero) digits is 80000, while the sum is 36.

The spelling of 221545540251 in words is "two hundred twenty-one billion, five hundred forty-five million, five hundred forty thousand, two hundred fifty-one".