21100670 has 16 divisors (see below), whose sum is σ = 38177568. Its totient is φ = 8396640.

The previous prime is 21100657. The next prime is 21100687. The reversal of 21100670 is 7600112.

It is a happy number.

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, 3386 + ... + 7325.

It is an arithmetic number, because the mean of its divisors is an integer number (2386098).

Almost surely, 2^21100670 is an apocalyptic number.

21100670 is a deficient number, since it is larger than the sum of its proper divisors (17076898).

21100670 is a wasteful number, since it uses less digits than its factorization.

21100670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10915.

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 21100670 is about 4593.5465601211. The cubic root of 21100670 is about 276.3325736107.

Adding to 21100670 its reverse (7600112), we get a palindrome (28700782).

The spelling of 21100670 in words is "twenty-one million, one hundred thousand, six hundred seventy".