142221531 has 4 divisors (see below), whose sum is σ = 189628712. Its totient is φ = 94814352.

The previous prime is 142221529. The next prime is 142221533. The reversal of 142221531 is 135122241.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 135122241 = 3 ⋅45040747.

It is an interprime number because it is at equal distance from previous prime (142221529) and next prime (142221533).

It is not a de Polignac number, because 142221531 - 2¹ = 142221529 is a prime.

It is a super-2 number, since 2×142221531² = 40453927759967922, 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 = 142221498 and 142221507.

It is not an unprimeable number, because it can be changed into a prime (142221533) 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 3 ways as a sum of consecutive naturals, for example, 23703586 + ... + 23703591.

It is an arithmetic number, because the mean of its divisors is an integer number (47407178).

Almost surely, 2^142221531 is an apocalyptic number.

142221531 is a deficient number, since it is larger than the sum of its proper divisors (47407181).

142221531 is an equidigital number, since it uses as much as digits as its factorization.

142221531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47407180.

The product of its digits is 480, while the sum is 21.

The square root of 142221531 is about 11925.6668995910. Note that the first 3 decimals coincide. The cubic root of 142221531 is about 521.9815065159.

Adding to 142221531 its reverse (135122241), we get a palindrome (277343772).

It can be divided in two parts, 14222 and 1531, that added together give a triangular number (15753 = T₁₇₇).

The spelling of 142221531 in words is "one hundred forty-two million, two hundred twenty-one thousand, five hundred thirty-one".