21503042 has 8 divisors (see below), whose sum is σ = 35186832. Its totient is φ = 9774100.

The previous prime is 21503039. The next prime is 21503051. The reversal of 21503042 is 24030512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21503042.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 488684 + ... + 488727.

It is an arithmetic number, because the mean of its divisors is an integer number (4398354).

Almost surely, 2^21503042 is an apocalyptic number.

21503042 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21503042 is a deficient number, since it is larger than the sum of its proper divisors (13683790).

21503042 is a wasteful number, since it uses less digits than its factorization.

21503042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 977424.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 21503042 is about 4637.1372634417. The cubic root of 21503042 is about 278.0780020237.

Adding to 21503042 its reverse (24030512), we get a palindrome (45533554).

The spelling of 21503042 in words is "twenty-one million, five hundred three thousand, forty-two".