151236221 has 4 divisors (see below), whose sum is σ = 151573500. Its totient is φ = 150898944.

The previous prime is 151236193. The next prime is 151236223. The reversal of 151236221 is 122632151.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122632151 = 8693 ⋅14107.

It can be written as a sum of positive squares in 2 ways, for example, as 68244121 + 82992100 = 8261^2 + 9110^2 .

It is a cyclic number.

It is not a de Polignac number, because 151236221 - 2¹⁸ = 150974077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (151236223) 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, 167966 + ... + 168863.

It is an arithmetic number, because the mean of its divisors is an integer number (37893375).

Almost surely, 2^151236221 is an apocalyptic number.

It is an amenable number.

151236221 is a deficient number, since it is larger than the sum of its proper divisors (337279).

151236221 is an equidigital number, since it uses as much as digits as its factorization.

151236221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337278.

The product of its digits is 720, while the sum is 23.

The square root of 151236221 is about 12297.8136674776. The cubic root of 151236221 is about 532.7849383512.

Adding to 151236221 its reverse (122632151), we get a palindrome (273868372).

The spelling of 151236221 in words is "one hundred fifty-one million, two hundred thirty-six thousand, two hundred twenty-one".