21248851 has 16 divisors (see below), whose sum is σ = 23889600. Its totient is φ = 18764928.

The previous prime is 21248831. The next prime is 21248879. The reversal of 21248851 is 15884212.

It is not a de Polignac number, because 21248851 - 2⁵ = 21248819 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21248831) 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, 59010 + ... + 59368.

It is an arithmetic number, because the mean of its divisors is an integer number (1493100).

Almost surely, 2^21248851 is an apocalyptic number.

21248851 is a deficient number, since it is larger than the sum of its proper divisors (2640749).

21248851 is a wasteful number, since it uses less digits than its factorization.

21248851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 558.

The product of its digits is 5120, while the sum is 31.

The square root of 21248851 is about 4609.6476004137. The cubic root of 21248851 is about 276.9779205381.

The spelling of 21248851 in words is "twenty-one million, two hundred forty-eight thousand, eight hundred fifty-one".