21142286531 has 4 divisors (see below), whose sum is σ = 21142640712. Its totient is φ = 21141932352.

The previous prime is 21142286507. The next prime is 21142286563. The reversal of 21142286531 is 13568224112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21142286531 is a prime.

It is a super-2 number, since 2×21142286531² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21142286491 and 21142286500.

It is not an unprimeable number, because it can be changed into a prime (21142286131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63086 + ... + 215091.

It is an arithmetic number, because the mean of its divisors is an integer number (5285660178).

Almost surely, 2^21142286531 is an apocalyptic number.

21142286531 is a deficient number, since it is larger than the sum of its proper divisors (354181).

21142286531 is an equidigital number, since it uses as much as digits as its factorization.

21142286531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354180.

The product of its digits is 23040, while the sum is 35.

The spelling of 21142286531 in words is "twenty-one billion, one hundred forty-two million, two hundred eighty-six thousand, five hundred thirty-one".