22021545 has 96 divisors (see below), whose sum is σ = 46801152. Its totient is φ = 8626176.

The previous prime is 22021543. The next prime is 22021561. The reversal of 22021545 is 54512022.

It is a happy number.

It is not a de Polignac number, because 22021545 - 2¹ = 22021543 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22021541) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 301629 + ... + 301701.

It is an arithmetic number, because the mean of its divisors is an integer number (487512).

Almost surely, 2^22021545 is an apocalyptic number.

It is an amenable number.

22021545 is an abundant number, since it is smaller than the sum of its proper divisors (24779607).

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

22021545 is a wasteful number, since it uses less digits than its factorization.

22021545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 22021545 is about 4692.7119025144. The cubic root of 22021545 is about 280.2953728246.

Adding to 22021545 its sum of digits (21), we get a triangular number (22021566 = T₆₆₃₆).

Adding to 22021545 its reverse (54512022), we get a palindrome (76533567).

The spelling of 22021545 in words is "twenty-two million, twenty-one thousand, five hundred forty-five".