21304778530 has 32 divisors (see below), whose sum is σ = 44252492544. Its totient is φ = 7233575616.

The previous prime is 21304778431. The next prime is 21304778531. The reversal of 21304778530 is 3587740312.

It is a happy number.

It is a super-3 number, since 3×21304778530³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21304778531) 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, 1470237 + ... + 1484656.

It is an arithmetic number, because the mean of its divisors is an integer number (1382890392).

Almost surely, 2^21304778530 is an apocalyptic number.

21304778530 is an abundant number, since it is smaller than the sum of its proper divisors (22947714014).

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

21304778530 is a wasteful number, since it uses less digits than its factorization.

21304778530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2955010.

The product of its (nonzero) digits is 141120, while the sum is 40.

The spelling of 21304778530 in words is "twenty-one billion, three hundred four million, seven hundred seventy-eight thousand, five hundred thirty".