21012321330 has 384 divisors, whose sum is σ = 73818501120. Its totient is φ = 4004743680.

The previous prime is 21012321289. The next prime is 21012321371. The reversal of 21012321330 is 3312321012.

21012321330 is a `hidden beast` number, since 2 + 1 + 0 + 12 + 321 + 330 = 666.

It is an interprime number because it is at equal distance from previous prime (21012321289) and next prime (21012321371).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 16125459 + ... + 16126761.

It is an arithmetic number, because the mean of its divisors is an integer number (192235680).

Almost surely, 2^21012321330 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21012321330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36909250560).

21012321330 is an abundant number, since it is smaller than the sum of its proper divisors (52806179790).

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

21012321330 is a wasteful number, since it uses less digits than its factorization.

21012321330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1526 (or 1523 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21012321330 its reverse (3312321012), we get a palindrome (24324642342).

The spelling of 21012321330 in words is "twenty-one billion, twelve million, three hundred twenty-one thousand, three hundred thirty".