21050144531 has 8 divisors (see below), whose sum is σ = 22679524560. Its totient is φ = 19422212832.

The previous prime is 21050144513. The next prime is 21050144543. The reversal of 21050144531 is 13544105012.

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

It is a cyclic number.

It is not a de Polignac number, because 21050144531 - 2²² = 21045950227 is a prime.

It is a super-2 number, since 2×21050144531² (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 21050144531.

It is not an unprimeable number, because it can be changed into a prime (21050144231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 331796 + ... + 390113.

It is an arithmetic number, because the mean of its divisors is an integer number (2834940570).

Almost surely, 2^21050144531 is an apocalyptic number.

21050144531 is a deficient number, since it is larger than the sum of its proper divisors (1629380029).

21050144531 is a wasteful number, since it uses less digits than its factorization.

21050144531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 724165.

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 21050144531 its reverse (13544105012), we get a palindrome (34594249543).

The spelling of 21050144531 in words is "twenty-one billion, fifty million, one hundred forty-four thousand, five hundred thirty-one".