22721028 has 48 divisors (see below), whose sum is σ = 59195136. Its totient is φ = 6723360.

The previous prime is 22721021. The next prime is 22721029. The reversal of 22721028 is 82012722.

It is a happy number.

It is a super-2 number, since 2×22721028² = 1032490226753568, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 22720989 and 22721007.

It is not an unprimeable number, because it can be changed into a prime (22721021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3675 + ... + 7677.

It is an arithmetic number, because the mean of its divisors is an integer number (1233232).

Almost surely, 2^22721028 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 22721028, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29597568).

22721028 is an abundant number, since it is smaller than the sum of its proper divisors (36474108).

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

22721028 is a wasteful number, since it uses less digits than its factorization.

22721028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4064 (or 4062 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 22721028 is about 4766.6579487100. The cubic root of 22721028 is about 283.2322216681.

The spelling of 22721028 in words is "twenty-two million, seven hundred twenty-one thousand, twenty-eight".