21417012 has 18 divisors (see below), whose sum is σ = 54137538. Its totient is φ = 7138992.

The previous prime is 21416999. The next prime is 21417023. The reversal of 21417012 is 21071412.

It can be written as a sum of positive squares in only one way, i.e., 18714276 + 2702736 = 4326^2 + 1644^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 297423 + ... + 297494.

It is an arithmetic number, because the mean of its divisors is an integer number (3007641).

Almost surely, 2^21417012 is an apocalyptic number.

It is an amenable number.

21417012 is an abundant number, since it is smaller than the sum of its proper divisors (32720526).

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

21417012 is a wasteful number, since it uses less digits than its factorization.

21417012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 594927 (or 594922 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 21417012 is about 4627.8517694498. The cubic root of 21417012 is about 277.7066588183.

Adding to 21417012 its reverse (21071412), we get a palindrome (42488424).

The spelling of 21417012 in words is "twenty-one million, four hundred seventeen thousand, twelve".