21223015530 has 32 divisors (see below), whose sum is σ = 50943069504. Its totient is φ = 5658600576.

The previous prime is 21223015519. The next prime is 21223015553. The reversal of 21223015530 is 3551032212.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21223015530.

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, 157494 + ... + 259326.

It is an arithmetic number, because the mean of its divisors is an integer number (1591970922).

Almost surely, 2^21223015530 is an apocalyptic number.

21223015530 is an abundant number, since it is smaller than the sum of its proper divisors (29720053974).

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

21223015530 is a wasteful number, since it uses less digits than its factorization.

21223015530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108790.

The product of its (nonzero) digits is 1800, while the sum is 24.

Adding to 21223015530 its reverse (3551032212), we get a palindrome (24774047742).

The spelling of 21223015530 in words is "twenty-one billion, two hundred twenty-three million, fifteen thousand, five hundred thirty".