21049868 has 24 divisors (see below), whose sum is σ = 43459584. Its totient is φ = 8730000.

The previous prime is 21049841. The next prime is 21049883. The reversal of 21049868 is 86894012.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11258 + ... + 12993.

It is an arithmetic number, because the mean of its divisors is an integer number (1810816).

Almost surely, 2^21049868 is an apocalyptic number.

21049868 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21049868 is an abundant number, since it is smaller than the sum of its proper divisors (22409716).

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

21049868 is a wasteful number, since it uses less digits than its factorization.

21049868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24293 (or 24291 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 21049868 is about 4588.0135134936. The cubic root of 21049868 is about 276.1106291785.

The spelling of 21049868 in words is "twenty-one million, forty-nine thousand, eight hundred sixty-eight".