21352918356 has 432 divisors, whose sum is σ = 72466954560. Its totient is φ = 5434490880.

The previous prime is 21352918351. The next prime is 21352918393. The reversal of 21352918356 is 65381925312.

21352918356 is a `hidden beast` number, since 2 + 1 + 3 + 5 + 291 + 8 + 356 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21352918351) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 27766740 + ... + 27767508.

It is an arithmetic number, because the mean of its divisors is an integer number (167747580).

Almost surely, 2^21352918356 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 21352918356, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36233477280).

21352918356 is an abundant number, since it is smaller than the sum of its proper divisors (51114036204).

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

21352918356 is a wasteful number, since it uses less digits than its factorization.

21352918356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 866 (or 845 counting only the distinct ones).

The product of its digits is 388800, while the sum is 45.

The spelling of 21352918356 in words is "twenty-one billion, three hundred fifty-two million, nine hundred eighteen thousand, three hundred fifty-six".