21293078352 has 160 divisors (see below), whose sum is σ = 68655605760. Its totient is φ = 5536581120.

The previous prime is 21293078269. The next prime is 21293078353. The reversal of 21293078352 is 25387039212.

It is a super-2 number, since 2×21293078352² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21293078353) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 275799 + ... + 344457.

It is an arithmetic number, because the mean of its divisors is an integer number (429097536).

Almost surely, 2^21293078352 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21293078352, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34327802880).

21293078352 is an abundant number, since it is smaller than the sum of its proper divisors (47362527408).

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

21293078352 is a wasteful number, since it uses less digits than its factorization.

21293078352 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68761 (or 68755 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 42.

The spelling of 21293078352 in words is "twenty-one billion, two hundred ninety-three million, seventy-eight thousand, three hundred fifty-two".