21008292 has 48 divisors (see below), whose sum is σ = 51717120. Its totient is φ = 6624288.

The previous prime is 21008291. The next prime is 21008293. The reversal of 21008292 is 29280012.

It is an interprime number because it is at equal distance from previous prime (21008291) and next prime (21008293).

It is a super-3 number, since 3×21008292³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21008291) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28059 + ... + 28797.

It is an arithmetic number, because the mean of its divisors is an integer number (1077440).

Almost surely, 2^21008292 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 21008292, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25858560).

21008292 is an abundant number, since it is smaller than the sum of its proper divisors (30708828).

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

21008292 is a wasteful number, since it uses less digits than its factorization.

21008292 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 872 (or 870 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 21008292 is about 4583.4803370365. The cubic root of 21008292 is about 275.9287255570.

The spelling of 21008292 in words is "twenty-one million, eight thousand, two hundred ninety-two".