21004241531 has 16 divisors (see below), whose sum is σ = 25985340864. Its totient is φ = 16532619264.

The previous prime is 21004241521. The next prime is 21004241537. The reversal of 21004241531 is 13514240012.

It is not a de Polignac number, because 21004241531 - 2¹⁰ = 21004240507 is a prime.

It is a super-2 number, since 2×21004241531² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21004241497 and 21004241506.

It is not an unprimeable number, because it can be changed into a prime (21004241537) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 580406 + ... + 615531.

It is an arithmetic number, because the mean of its divisors is an integer number (1624083804).

Almost surely, 2^21004241531 is an apocalyptic number.

21004241531 is a deficient number, since it is larger than the sum of its proper divisors (4981099333).

21004241531 is a wasteful number, since it uses less digits than its factorization.

21004241531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1196150.

The product of its (nonzero) digits is 960, while the sum is 23.

Adding to 21004241531 its reverse (13514240012), we get a palindrome (34518481543).

The spelling of 21004241531 in words is "twenty-one billion, four million, two hundred forty-one thousand, five hundred thirty-one".