21772545 has 16 divisors (see below), whose sum is σ = 34913472. Its totient is φ = 11586240.

The previous prime is 21772519. The next prime is 21772549. The reversal of 21772545 is 54527712.

It is not a de Polignac number, because 21772545 - 2⁶ = 21772481 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21772549) 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, 6774 + ... + 9456.

It is an arithmetic number, because the mean of its divisors is an integer number (2182092).

Almost surely, 2^21772545 is an apocalyptic number.

It is an amenable number.

21772545 is a deficient number, since it is larger than the sum of its proper divisors (13140927).

21772545 is a wasteful number, since it uses less digits than its factorization.

21772545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3232.

The product of its digits is 19600, while the sum is 33.

The square root of 21772545 is about 4666.1059782221. The cubic root of 21772545 is about 279.2349224454.

The spelling of 21772545 in words is "twenty-one million, seven hundred seventy-two thousand, five hundred forty-five".