22161240 has 48 divisors (see below), whose sum is σ = 72025200. Its totient is φ = 5909568.

The previous prime is 22161229. The next prime is 22161241. The reversal of 22161240 is 4216122.

It is a super-2 number, since 2×22161240² = 982241116675200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22161241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30420 + ... + 31139.

It is an arithmetic number, because the mean of its divisors is an integer number (1500525).

Almost surely, 2^22161240 is an apocalyptic number.

22161240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

22161240 is an abundant number, since it is smaller than the sum of its proper divisors (49863960).

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

22161240 is a wasteful number, since it uses less digits than its factorization.

22161240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61576 (or 61569 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 22161240 is about 4707.5726229130. The cubic root of 22161240 is about 280.8868141730.

Adding to 22161240 its reverse (4216122), we get a palindrome (26377362).

The spelling of 22161240 in words is "twenty-two million, one hundred sixty-one thousand, two hundred forty".