21150343531 has 4 divisors (see below), whose sum is σ = 21150643072. Its totient is φ = 21150043992.

The previous prime is 21150343471. The next prime is 21150343667. The reversal of 21150343531 is 13534305112.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21150343531 - 2¹⁵ = 21150310763 is a prime.

It is a super-2 number, since 2×21150343531² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21150343531.

It is not an unprimeable number, because it can be changed into a prime (21150343831) 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, 21205 + ... + 206761.

It is an arithmetic number, because the mean of its divisors is an integer number (5287660768).

Almost surely, 2^21150343531 is an apocalyptic number.

21150343531 is a deficient number, since it is larger than the sum of its proper divisors (299541).

21150343531 is a wasteful number, since it uses less digits than its factorization.

21150343531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299540.

The product of its (nonzero) digits is 5400, while the sum is 28.

Adding to 21150343531 its reverse (13534305112), we get a palindrome (34684648643).

The spelling of 21150343531 in words is "twenty-one billion, one hundred fifty million, three hundred forty-three thousand, five hundred thirty-one".