21810578448 has 160 divisors (see below), whose sum is σ = 59981160960. Its totient is φ = 6817054720.

The previous prime is 21810578411. The next prime is 21810578479. The reversal of 21810578448 is 84487501812.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a junction number, because it is equal to n+sod(n) for n = 21810578397 and 21810578406.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14666761 + ... + 14668247.

It is an arithmetic number, because the mean of its divisors is an integer number (374882256).

Almost surely, 2^21810578448 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 21810578448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29990580480).

21810578448 is an abundant number, since it is smaller than the sum of its proper divisors (38170582512).

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

21810578448 is a wasteful number, since it uses less digits than its factorization.

21810578448 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1825 (or 1819 counting only the distinct ones).

The product of its (nonzero) digits is 573440, while the sum is 48.

The spelling of 21810578448 in words is "twenty-one billion, eight hundred ten million, five hundred seventy-eight thousand, four hundred forty-eight".