21378298380 has 96 divisors (see below), whose sum is σ = 60660036864. Its totient is φ = 5624795904.

The previous prime is 21378298373. The next prime is 21378298423. The reversal of 21378298380 is 8389287312.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4514494 + ... + 4519226.

It is an arithmetic number, because the mean of its divisors is an integer number (631875384).

Almost surely, 2^21378298380 is an apocalyptic number.

21378298380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21378298380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30330018432).

21378298380 is an abundant number, since it is smaller than the sum of its proper divisors (39281738484).

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

21378298380 is a wasteful number, since it uses less digits than its factorization.

21378298380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5735 (or 5733 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 51.

The spelling of 21378298380 in words is "twenty-one billion, three hundred seventy-eight million, two hundred ninety-eight thousand, three hundred eighty".