21015148 has 72 divisors (see below), whose sum is σ = 48045312. Its totient is φ = 7812000.

The previous prime is 21015143. The next prime is 21015161. The reversal of 21015148 is 84151012.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21015143) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 295953 + ... + 296023.

It is an arithmetic number, because the mean of its divisors is an integer number (667296).

Almost surely, 2^21015148 is an apocalyptic number.

21015148 is a gapful number since it is divisible by the number (28) 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 21015148, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24022656).

21015148 is an abundant number, since it is smaller than the sum of its proper divisors (27030164).

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

21015148 is a wasteful number, since it uses less digits than its factorization.

21015148 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 22.

The square root of 21015148 is about 4584.2281793122. The cubic root of 21015148 is about 275.9587384933.

The spelling of 21015148 in words is "twenty-one million, fifteen thousand, one hundred forty-eight".