21516022 has 8 divisors (see below), whose sum is σ = 35208072. Its totient is φ = 9780000.

The previous prime is 21515983. The next prime is 21516029. The reversal of 21516022 is 22061512.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21516029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 488979 + ... + 489022.

It is an arithmetic number, because the mean of its divisors is an integer number (4401009).

Almost surely, 2^21516022 is an apocalyptic number.

21516022 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21516022 is a deficient number, since it is larger than the sum of its proper divisors (13692050).

21516022 is a wasteful number, since it uses less digits than its factorization.

21516022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 978014.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 21516022 is about 4638.5366226861. The cubic root of 21516022 is about 278.1339433559.

Adding to 21516022 its reverse (22061512), we get a palindrome (43577534).

Subtracting 21516022 from its reverse (22061512), we obtain a triangular number (545490 = T₁₀₄₄).

The spelling of 21516022 in words is "twenty-one million, five hundred sixteen thousand, twenty-two".