21078948 has 96 divisors (see below), whose sum is σ = 57480192. Its totient is φ = 5948800.

The previous prime is 21078947. The next prime is 21078949. The reversal of 21078948 is 84987012.

It is an interprime number because it is at equal distance from previous prime (21078947) and next prime (21078949).

It is not an unprimeable number, because it can be changed into a prime (21078947) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 160843 + ... + 160973.

It is an arithmetic number, because the mean of its divisors is an integer number (598752).

Almost surely, 2^21078948 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 21078948, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28740096).

21078948 is an abundant number, since it is smaller than the sum of its proper divisors (36401244).

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

21078948 is a wasteful number, since it uses less digits than its factorization.

21078948 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 223 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 21078948 is about 4591.1815472708. The cubic root of 21078948 is about 276.2377179009.

The spelling of 21078948 in words is "twenty-one million, seventy-eight thousand, nine hundred forty-eight".