21426834 has 96 divisors (see below), whose sum is σ = 54074304. Its totient is φ = 5591040.

The previous prime is 21426827. The next prime is 21426841. The reversal of 21426834 is 43862412.

It is an interprime number because it is at equal distance from previous prime (21426827) and next prime (21426841).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 189562 + ... + 189674.

It is an arithmetic number, because the mean of its divisors is an integer number (563274).

Almost surely, 2^21426834 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21426834, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27037152).

21426834 is an abundant number, since it is smaller than the sum of its proper divisors (32647470).

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

21426834 is a wasteful number, since it uses less digits than its factorization.

21426834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172 (or 159 counting only the distinct ones).

The product of its digits is 9216, while the sum is 30.

The square root of 21426834 is about 4628.9128313244. The cubic root of 21426834 is about 277.7491051056.

The spelling of 21426834 in words is "twenty-one million, four hundred twenty-six thousand, eight hundred thirty-four".