21052948 has 36 divisors (see below), whose sum is σ = 43135092. Its totient is φ = 8964480.

The previous prime is 21052943. The next prime is 21052949. The reversal of 21052948 is 84925012.

It can be written as a sum of positive squares in 2 ways, for example, as 5466244 + 15586704 = 2338^2 + 3948^2 .

It is a super-3 number, since 3×21052948³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21052943) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 45438 + ... + 45898.

It is an arithmetic number, because the mean of its divisors is an integer number (1198197).

Almost surely, 2^21052948 is an apocalyptic number.

21052948 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 21052948, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21567546).

21052948 is an abundant number, since it is smaller than the sum of its proper divisors (22082144).

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

21052948 is a wasteful number, since it uses less digits than its factorization.

21052948 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 712 (or 703 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 21052948 is about 4588.3491584665. The cubic root of 21052948 is about 276.1240952845.

Subtracting 21052948 from its reverse (84925012), we obtain a square (63872064 = 7992²).

The spelling of 21052948 in words is "twenty-one million, fifty-two thousand, nine hundred forty-eight".