21122140 has 24 divisors (see below), whose sum is σ = 47769120. Its totient is φ = 7798848.

The previous prime is 21122111. The next prime is 21122161. The reversal of 21122140 is 4122112.

It is a happy number.

It is a super-2 number, since 2×21122140² = 892289596359200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a self number, because there is not a number n which added to its sum of digits gives 21122140.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40360 + ... + 40879.

It is an arithmetic number, because the mean of its divisors is an integer number (1990380).

Almost surely, 2^21122140 is an apocalyptic number.

21122140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21122140 is an abundant number, since it is smaller than the sum of its proper divisors (26646980).

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

21122140 is a wasteful number, since it uses less digits than its factorization.

21122140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81261 (or 81259 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 21122140 is about 4595.8829401977. The cubic root of 21122140 is about 276.4262649367.

Adding to 21122140 its reverse (4122112), we get a palindrome (25244252).

The spelling of 21122140 in words is "twenty-one million, one hundred twenty-two thousand, one hundred forty".