21702066 has 16 divisors (see below), whose sum is σ = 45688800. Its totient is φ = 6853248.

The previous prime is 21702059. The next prime is 21702067. The reversal of 21702066 is 66020712.

It is a happy number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21702067) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95071 + ... + 95298.

It is an arithmetic number, because the mean of its divisors is an integer number (2855550).

Almost surely, 2^21702066 is an apocalyptic number.

21702066 is an abundant number, since it is smaller than the sum of its proper divisors (23986734).

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

21702066 is a wasteful number, since it uses less digits than its factorization.

21702066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190393.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21702066 is about 4658.5476277484. The cubic root of 21702066 is about 278.9332968325.

Adding to 21702066 its reverse (66020712), we get a palindrome (87722778).

The spelling of 21702066 in words is "twenty-one million, seven hundred two thousand, sixty-six".