21010612 has 18 divisors (see below), whose sum is σ = 42772002. Its totient is φ = 9004464.

The previous prime is 21010609. The next prime is 21010663. The reversal of 21010612 is 21601012.

It can be written as a sum of positive squares in only one way, i.e., 10732176 + 10278436 = 3276^2 + 3206^2 .

It is a super-2 number, since 2×21010612² = 882891633229088, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21010592 and 21010601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 53403 + ... + 53794.

Almost surely, 2^21010612 is an apocalyptic number.

It is an amenable number.

21010612 is an abundant number, since it is smaller than the sum of its proper divisors (21761390).

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

21010612 is a wasteful number, since it uses less digits than its factorization.

21010612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107215 (or 107206 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 21010612 is about 4583.7334128415. The cubic root of 21010612 is about 275.9388823573.

Adding to 21010612 its reverse (21601012), we get a palindrome (42611624).

The spelling of 21010612 in words is "twenty-one million, ten thousand, six hundred twelve".