22001540 has 48 divisors (see below), whose sum is σ = 50972544. Its totient is φ = 7910400.

The previous prime is 22001533. The next prime is 22001597. The reversal of 22001540 is 4510022.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20825 + ... + 21855.

It is an arithmetic number, because the mean of its divisors is an integer number (1061928).

Almost surely, 2^22001540 is an apocalyptic number.

22001540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 22001540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25486272).

22001540 is an abundant number, since it is smaller than the sum of its proper divisors (28971004).

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

22001540 is a wasteful number, since it uses less digits than its factorization.

22001540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1148 (or 1146 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 14.

The square root of 22001540 is about 4690.5799215022. The cubic root of 22001540 is about 280.2104710048.

Adding to 22001540 its reverse (4510022), we get a palindrome (26511562).

The spelling of 22001540 in words is "twenty-two million, one thousand, five hundred forty".