21502452378 has 96 divisors (see below), whose sum is σ = 48780527040. Its totient is φ = 6310022400.

The previous prime is 21502452371. The next prime is 21502452443. The reversal of 21502452378 is 87325420512.

It is not an unprimeable number, because it can be changed into a prime (21502452371) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4134876 + ... + 4140072.

It is an arithmetic number, because the mean of its divisors is an integer number (508130490).

Almost surely, 2^21502452378 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21502452378, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24390263520).

21502452378 is an abundant number, since it is smaller than the sum of its proper divisors (27278074662).

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

21502452378 is a wasteful number, since it uses less digits than its factorization.

21502452378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5404 (or 5393 counting only the distinct ones).

The product of its (nonzero) digits is 134400, while the sum is 39.

The spelling of 21502452378 in words is "twenty-one billion, five hundred two million, four hundred fifty-two thousand, three hundred seventy-eight".