151221531 has 8 divisors (see below), whose sum is σ = 201686080. Its totient is φ = 100785672.

The previous prime is 151221529. The next prime is 151221533. The reversal of 151221531 is 135122151.

It is an interprime number because it is at equal distance from previous prime (151221529) and next prime (151221533).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 151221531 - 2¹ = 151221529 is a prime.

It is a super-2 number, since 2×151221531² = 45735902875967922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 151221498 and 151221507.

It is not an unprimeable number, because it can be changed into a prime (151221533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14400 + ... + 22578.

It is an arithmetic number, because the mean of its divisors is an integer number (25210760).

Almost surely, 2^151221531 is an apocalyptic number.

151221531 is a deficient number, since it is larger than the sum of its proper divisors (50464549).

151221531 is an equidigital number, since it uses as much as digits as its factorization.

151221531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14345.

The product of its digits is 300, while the sum is 21.

The square root of 151221531 is about 12297.2163923386. The cubic root of 151221531 is about 532.7676874922.

Adding to 151221531 its reverse (135122151), we get a palindrome (286343682).

It can be divided in two parts, 15122 and 1531, that added together give a triangular number (16653 = T₁₈₂).

The spelling of 151221531 in words is "one hundred fifty-one million, two hundred twenty-one thousand, five hundred thirty-one".