21510878382 has 36 divisors (see below), whose sum is σ = 54216195696. Its totient is φ = 6145965000.

The previous prime is 21510878371. The next prime is 21510878453. The reversal of 21510878382 is 28387801512.

21510878382 is a `hidden beast` number, since 21 + 510 + 87 + 8 + 38 + 2 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 12193494 + ... + 12195257.

It is an arithmetic number, because the mean of its divisors is an integer number (1506005436).

Almost surely, 2^21510878382 is an apocalyptic number.

21510878382 is an abundant number, since it is smaller than the sum of its proper divisors (32705317314).

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

21510878382 is a wasteful number, since it uses less digits than its factorization.

21510878382 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24388773 (or 24388763 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 45.

The spelling of 21510878382 in words is "twenty-one billion, five hundred ten million, eight hundred seventy-eight thousand, three hundred eighty-two".