21716278 has 16 divisors (see below), whose sum is σ = 35781120. Its totient is φ = 9839016.

The previous prime is 21716251. The next prime is 21716287. The reversal of 21716278 is 87261712.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11550 + ... + 13297.

It is an arithmetic number, because the mean of its divisors is an integer number (2236320).

Almost surely, 2^21716278 is an apocalyptic number.

21716278 is a deficient number, since it is larger than the sum of its proper divisors (14064842).

21716278 is a wasteful number, since it uses less digits than its factorization.

21716278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24891.

The product of its digits is 9408, while the sum is 34.

The square root of 21716278 is about 4660.0727462133. The cubic root of 21716278 is about 278.9941717585.

The spelling of 21716278 in words is "twenty-one million, seven hundred sixteen thousand, two hundred seventy-eight".