23221540 has 12 divisors (see below), whose sum is σ = 48765276. Its totient is φ = 9288608.

The previous prime is 23221537. The next prime is 23221631. The reversal of 23221540 is 4512232.

It can be written as a sum of positive squares in 2 ways, for example, as 6770404 + 16451136 = 2602^2 + 4056^2 .

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, 580519 + ... + 580558.

It is an arithmetic number, because the mean of its divisors is an integer number (4063773).

Almost surely, 2^23221540 is an apocalyptic number.

23221540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

23221540 is an abundant number, since it is smaller than the sum of its proper divisors (25543736).

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

23221540 is a wasteful number, since it uses less digits than its factorization.

23221540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1161086 (or 1161084 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 23221540 is about 4818.8733123003. The cubic root of 23221540 is about 285.2968692788.

Adding to 23221540 its reverse (4512232), we get a palindrome (27733772).

The spelling of 23221540 in words is "twenty-three million, two hundred twenty-one thousand, five hundred forty".