21541012 has 6 divisors (see below), whose sum is σ = 37696778. Its totient is φ = 10770504.

The previous prime is 21540983. The next prime is 21541019. The reversal of 21541012 is 21014512.

It can be written as a sum of positive squares in only one way, i.e., 15007876 + 6533136 = 3874^2 + 2556^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21541019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2692623 + ... + 2692630.

Almost surely, 2^21541012 is an apocalyptic number.

It is an amenable number.

21541012 is a deficient number, since it is larger than the sum of its proper divisors (16155766).

21541012 is a wasteful number, since it uses less digits than its factorization.

21541012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5385257 (or 5385255 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 21541012 is about 4641.2295784630. The cubic root of 21541012 is about 278.2415821819.

Adding to 21541012 its reverse (21014512), we get a palindrome (42555524).

The spelling of 21541012 in words is "twenty-one million, five hundred forty-one thousand, twelve".