21224145531 has 8 divisors (see below), whose sum is σ = 28317207040. Its totient is φ = 14140257192.

The previous prime is 21224145521. The next prime is 21224145587. The reversal of 21224145531 is 13554142212.

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

It is not a de Polignac number, because 21224145531 - 2³⁴ = 4044276347 is a prime.

It is a super-2 number, since 2×21224145531² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21224145521) 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, 2287891 + ... + 2297148.

It is an arithmetic number, because the mean of its divisors is an integer number (3539650880).

Almost surely, 2^21224145531 is an apocalyptic number.

21224145531 is a deficient number, since it is larger than the sum of its proper divisors (7093061509).

21224145531 is a wasteful number, since it uses less digits than its factorization.

21224145531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4586585.

The product of its digits is 9600, while the sum is 30.

Adding to 21224145531 its reverse (13554142212), we get a palindrome (34778287743).

The spelling of 21224145531 in words is "twenty-one billion, two hundred twenty-four million, one hundred forty-five thousand, five hundred thirty-one".