21320502 has 16 divisors (see below), whose sum is σ = 48732672. Its totient is φ = 6091560.

The previous prime is 21320491. The next prime is 21320513. The reversal of 21320502 is 20502312.

It is an interprime number because it is at equal distance from previous prime (21320491) and next prime (21320513).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 253774 + ... + 253857.

It is an arithmetic number, because the mean of its divisors is an integer number (3045792).

Almost surely, 2^21320502 is an apocalyptic number.

21320502 is an abundant number, since it is smaller than the sum of its proper divisors (27412170).

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

21320502 is a wasteful number, since it uses less digits than its factorization.

21320502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 507643.

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 21320502 is about 4617.4129120104. The cubic root of 21320502 is about 277.2888939032.

Adding to 21320502 its reverse (20502312), we get a palindrome (41822814).

The spelling of 21320502 in words is "twenty-one million, three hundred twenty thousand, five hundred two".