21286946 has 16 divisors (see below), whose sum is σ = 32568288. Its totient is φ = 10432800.

The previous prime is 21286943. The next prime is 21286949. The reversal of 21286946 is 64968212.

It is an interprime number because it is at equal distance from previous prime (21286943) and next prime (21286949).

It is not an unprimeable number, because it can be changed into a prime (21286943) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30461 + ... + 31151.

It is an arithmetic number, because the mean of its divisors is an integer number (2035518).

Almost surely, 2^21286946 is an apocalyptic number.

21286946 is a deficient number, since it is larger than the sum of its proper divisors (11281342).

21286946 is a wasteful number, since it uses less digits than its factorization.

21286946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 977.

The product of its digits is 41472, while the sum is 38.

The square root of 21286946 is about 4613.7778446735. Note that the first 3 decimals coincide. The cubic root of 21286946 is about 277.1433439859.

The spelling of 21286946 in words is "twenty-one million, two hundred eighty-six thousand, nine hundred forty-six".