21395862 has 48 divisors (see below), whose sum is σ = 49523760. Its totient is φ = 6656256.

The previous prime is 21395861. The next prime is 21395863. The reversal of 21395862 is 26859312.

It is an interprime number because it is at equal distance from previous prime (21395861) and next prime (21395863).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21395861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24538 + ... + 25394.

It is an arithmetic number, because the mean of its divisors is an integer number (1031745).

Almost surely, 2^21395862 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21395862, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24761880).

21395862 is an abundant number, since it is smaller than the sum of its proper divisors (28127898).

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

21395862 is a wasteful number, since it uses less digits than its factorization.

21395862 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 957 (or 954 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 21395862 is about 4625.5661275135. The cubic root of 21395862 is about 277.6152139065.

It can be divided in two parts, 2139 and 5862, that added together give a triangular number (8001 = T₁₂₆).

The spelling of 21395862 in words is "twenty-one million, three hundred ninety-five thousand, eight hundred sixty-two".