21045502 has 16 divisors (see below), whose sum is σ = 33541200. Its totient is φ = 9875520.

The previous prime is 21045487. The next prime is 21045517. The reversal of 21045502 is 20554012.

It is an interprime number because it is at equal distance from previous prime (21045487) and next prime (21045517).

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a self number, because there is not a number n which added to its sum of digits gives 21045502.

It is a congruent number.

It is an unprimeable number.

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, 1602 + ... + 6682.

It is an arithmetic number, because the mean of its divisors is an integer number (2096325).

Almost surely, 2^21045502 is an apocalyptic number.

21045502 is a deficient number, since it is larger than the sum of its proper divisors (12495698).

21045502 is a wasteful number, since it uses less digits than its factorization.

21045502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5211.

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 21045502 is about 4587.5376837689. The cubic root of 21045502 is about 276.0915382851.

Adding to 21045502 its reverse (20554012), we get a palindrome (41599514).

The spelling of 21045502 in words is "twenty-one million, forty-five thousand, five hundred two".