21071612 has 12 divisors (see below), whose sum is σ = 37157736. Its totient is φ = 10455120.

The previous prime is 21071587. The next prime is 21071621. The reversal of 21071612 is 21617012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19583 + ... + 20630.

It is an arithmetic number, because the mean of its divisors is an integer number (3096478).

Almost surely, 2^21071612 is an apocalyptic number.

It is an amenable number.

21071612 is a deficient number, since it is larger than the sum of its proper divisors (16086124).

21071612 is a wasteful number, since it uses less digits than its factorization.

21071612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40348 (or 40346 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 21071612 is about 4590.3825548640. The cubic root of 21071612 is about 276.2056683091.

Adding to 21071612 its reverse (21617012), we get a palindrome (42688624).

The spelling of 21071612 in words is "twenty-one million, seventy-one thousand, six hundred twelve".