21413502 has 48 divisors (see below), whose sum is σ = 51262848. Its totient is φ = 6405840.

The previous prime is 21413479. The next prime is 21413531. The reversal of 21413502 is 20531412.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15783 + ... + 17085.

It is an arithmetic number, because the mean of its divisors is an integer number (1067976).

Almost surely, 2^21413502 is an apocalyptic number.

21413502 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21413502, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25631424).

21413502 is an abundant number, since it is smaller than the sum of its proper divisors (29849346).

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

21413502 is a wasteful number, since it uses less digits than its factorization.

21413502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1405 (or 1402 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21413502 is about 4627.4725282815. The cubic root of 21413502 is about 277.6914870220.

Adding to 21413502 its reverse (20531412), we get a palindrome (41944914).

The spelling of 21413502 in words is "twenty-one million, four hundred thirteen thousand, five hundred two".