21820022 has 8 divisors (see below), whose sum is σ = 37405776. Its totient is φ = 9351432.

The previous prime is 21820013. The next prime is 21820033. The reversal of 21820022 is 22002812.

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

It is a super-2 number, since 2×21820022² = 952226720160968, which contains 22 as substring.

It is a congruent number.

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, 779273 + ... + 779300.

It is an arithmetic number, because the mean of its divisors is an integer number (4675722).

Almost surely, 2^21820022 is an apocalyptic number.

21820022 is a deficient number, since it is larger than the sum of its proper divisors (15585754).

21820022 is a wasteful number, since it uses less digits than its factorization.

21820022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1558582.

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 21820022 is about 4671.1906405113. The cubic root of 21820022 is about 279.4377407481.

Adding to 21820022 its reverse (22002812), we get a palindrome (43822834).

The spelling of 21820022 in words is "twenty-one million, eight hundred twenty thousand, twenty-two".