21240232530 has 32 divisors (see below), whose sum is σ = 55610791488. Its totient is φ = 5149147200.

The previous prime is 21240232529. The next prime is 21240232547. The reversal of 21240232530 is 3523204212.

It is a super-2 number, since 2×21240232530² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21240232530.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32181841 + ... + 32182500.

It is an arithmetic number, because the mean of its divisors is an integer number (1737837234).

Almost surely, 2^21240232530 is an apocalyptic number.

21240232530 is an abundant number, since it is smaller than the sum of its proper divisors (34370558958).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21240232530 is a wasteful number, since it uses less digits than its factorization.

21240232530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64364362.

The product of its (nonzero) digits is 2880, while the sum is 24.

Adding to 21240232530 its reverse (3523204212), we get a palindrome (24763436742).

The spelling of 21240232530 in words is "twenty-one billion, two hundred forty million, two hundred thirty-two thousand, five hundred thirty".