21007134 has 64 divisors (see below), whose sum is σ = 48787200. Its totient is φ = 6695136.

The previous prime is 21007123. The next prime is 21007139. The reversal of 21007134 is 43170012.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21007139) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 192672 + ... + 192780.

It is an arithmetic number, because the mean of its divisors is an integer number (762300).

Almost surely, 2^21007134 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21007134, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24393600).

21007134 is an abundant number, since it is smaller than the sum of its proper divisors (27780066).

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

21007134 is a wasteful number, since it uses less digits than its factorization.

21007134 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246 (or 240 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 21007134 is about 4583.3540120746. The cubic root of 21007134 is about 275.9236556329.

Adding to 21007134 its reverse (43170012), we get a palindrome (64177146).

The spelling of 21007134 in words is "twenty-one million, seven thousand, one hundred thirty-four".