21290502 has 16 divisors (see below), whose sum is σ = 44432640. Its totient is φ = 6788232.

The previous prime is 21290501. The next prime is 21290509. The reversal of 21290502 is 20509212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21290501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77002 + ... + 77277.

It is an arithmetic number, because the mean of its divisors is an integer number (2777040).

Almost surely, 2^21290502 is an apocalyptic number.

21290502 is an abundant number, since it is smaller than the sum of its proper divisors (23142138).

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

21290502 is a wasteful number, since it uses less digits than its factorization.

21290502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154307.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 21290502 is about 4614.1631960736. The cubic root of 21290502 is about 277.1587754599.

Adding to 21290502 its reverse (20509212), we get a palindrome (41799714).

The spelling of 21290502 in words is "twenty-one million, two hundred ninety thousand, five hundred two".