21625166 has 16 divisors (see below), whose sum is σ = 34121088. Its totient is φ = 10264800.

The previous prime is 21625117. The next prime is 21625181. The reversal of 21625166 is 66152612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5 + ... + 6576.

It is an arithmetic number, because the mean of its divisors is an integer number (2132568).

Almost surely, 2^21625166 is an apocalyptic number.

21625166 is a deficient number, since it is larger than the sum of its proper divisors (12495922).

21625166 is a wasteful number, since it uses less digits than its factorization.

21625166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6667.

The product of its digits is 4320, while the sum is 29.

The square root of 21625166 is about 4650.2866578309. The cubic root of 21625166 is about 278.6034456547.

Adding to 21625166 its reverse (66152612), we get a palindrome (87777778).

The spelling of 21625166 in words is "twenty-one million, six hundred twenty-five thousand, one hundred sixty-six".