151688221 has 2 divisors, whose sum is σ = 151688222. Its totient is φ = 151688220.

The previous prime is 151688209. The next prime is 151688237. The reversal of 151688221 is 122886151.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 147744025 + 3944196 = 12155^2 + 1986^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-151688221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (151688291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 75844110 + 75844111.

It is an arithmetic number, because the mean of its divisors is an integer number (75844111).

Almost surely, 2^151688221 is an apocalyptic number.

It is an amenable number.

151688221 is a deficient number, since it is larger than the sum of its proper divisors (1).

151688221 is an equidigital number, since it uses as much as digits as its factorization.

151688221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7680, while the sum is 34.

The square root of 151688221 is about 12316.1772072344. The cubic root of 151688221 is about 533.3151889227.

The spelling of 151688221 in words is "one hundred fifty-one million, six hundred eighty-eight thousand, two hundred twenty-one".