21610945 has 16 divisors (see below), whose sum is σ = 27106560. Its totient is φ = 16519104.

The previous prime is 21610943. The next prime is 21610949. The reversal of 21610945 is 54901612.

It is a cyclic number.

It is not a de Polignac number, because 21610945 - 2¹ = 21610943 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (21610943) 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, 14212 + ... + 15658.

It is an arithmetic number, because the mean of its divisors is an integer number (1694160).

Almost surely, 2^21610945 is an apocalyptic number.

It is an amenable number.

21610945 is a deficient number, since it is larger than the sum of its proper divisors (5495615).

21610945 is a wasteful number, since it uses less digits than its factorization.

21610945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1584.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 21610945 is about 4648.7573608439. The cubic root of 21610945 is about 278.5423611385.

The spelling of 21610945 in words is "twenty-one million, six hundred ten thousand, nine hundred forty-five".